iitkiitk

Bioinorganic Laboratory
Department of Chemistry
Indian Institute of Technology Kanpur

Full List of Publications

Review/Perspective Articles:

1.    Hydroxo-bridged diiron(III) and dimanganese(III) bisporphyrins: modulation of metal spins by counter anions

         F. S. T. Khan, T. Guchhait, S. Sasmal and S. P. Rath *

         Dalton Trans. 2017, 46, 1012-1037.  Full Article (Invited Perspective and Front Cover Article)

A brief account has been presented on how the inter-heme interactions in μ-hydroxo diiron(III) bisporphyrins and counter anions can induce significant change in the structure and properties including the iron spin state without affecting the overall topology.


2.    Oxo- and hydroxo-bridged diiron(III) porphyrin dimers: inorganic and bio-inorganic perspectives and effects of intermacrocyclic interactions        

         T. Guchhait, S. Sasmal, F. S. T. Khan and S. P. Rath *

          Coord. Chem. Rev. 2017, 337, 112-144.  Full Article

The fascinating chemistry of the oxo and hydroxo-bridged diheme centers, covalently connected through bridges varying in lengths and flexibility, has attracted much attention in recent times and a comprehensive review on their syntheses, structures and spectral properties is presented here.


3.    An Ethane-bridged Porphyrin Dimer as Model of Di-heme Proteins: Inorganic and Bioinorganic Perspectives and Consequences of Heme-Heme Interactions

          D. Sil and S. P. Rath *

          Dalton Trans. 2015, 44, 16195-16211. Full Article (Invited Perspective Article)

A brief account of our recent efforts on how inter-heme interactions can possibly change the structure and functional properties of the individual heme centers in a highly flexible ethane-bridged porphyrin dimer has been presented.


Complete List of Publications:

95.    Silver(III)···Silver(III) Interaction Stabilizes the Syn-form in a Porphyrin Dimer Upon Oxidation

          A. K. Singh, F. S. T. Khan and S. P. Rath*

          Angew. Chem. Int. Ed. 2017, 56, 8849-8854.  Full Article

       

Meeting at the bridge: Ethane-bridged silver(III) porphyrin dimer exhibits significant metallophilic interaction that brings two porphyrin rings on top of each other with short Ag(III)···Ag(III) distance attributed to the overlap of dz2 metal orbital. The complex displays an intense emission peak at 546 nm at 77 K in the photoluminescence study.


94.    Intermacrocyclic Interaction Triggers Facile One-pot Synthesis of a Chlorin-Porphyrin Heterodimer

          Y. A. Pandit, S. Sanfui and S. P. Rath*

        Chem. Eur. J. 2017, 23, 13415-13422.  Full Article

Highly reactive π-cation radicals: Intermacrocyclic interaction stimulates the quantitative one-pot synthesis of a new series of fully π-conjugated unsymmetric chlorin-porphyrin heterodimers by using mild oxidants such as iodine at room temperature.


93.    Probing Bis-FeIV MauG: Isolation of Highly Reactive Radical Intermediates

          T. Guchhait, S. Sarkar, Y. A. Pandit and S. P. Rath*

         Chem. Eur. J. (Communication) 2017, 23, 10270-10275.  Full Article

Step-wise oxidations: Step-wise oxidations of a synthetic analog of diheme MauG enable isolation and structural characterizations of dication diradical, indolizinium-fused chlorin-porphyrin heterodimer and spiro-porphyrinato heterodimer. The active role played by the bridge in the electronic communication has been explored.


92.    Cyclic Bisporphyrin Based Flexible Molecular Containers: Controlling Guest Arrangements and Supramolecular Catalysis by Tuning Cavity Size

          P. Mondal, S. Sarkar and S. P. Rath*

             Chem. Eur. J. 2017, 23, 7093-7103. Full Article Highlighted in Synfacts 2017, 13, 816

Accommodating substrates: Three cyclic zinc(II) bisporphyrins (CB) with flexible linkers are employed as artificial molecular containers. Interestingly, the arrangements of the guests and the reactivity inside the containers are significantly influenced by the cavity size.


91.    Hydroxo-bridged diiron(III) and dimanganese(III) bisporphyrins: modulation of metal spins by counter anions

           F. S. T. Khan, T. Guchhait, S. Sasmal and S. P. Rath *

         Dalton Trans. 2017, 46, 1012-1037.  Full Article (Invited Perspective and Front Cover Article)

A brief account has been presented on how the inter-heme interactions in μ-hydroxo diiron(III) bisporphyrins and counter anions can induce significant change in the structure and properties including the iron spin state without affecting the overall topology.


90.    Oxo- and hydroxo-bridged diiron(III) porphyrin dimers: inorganic and bio-inorganic perspectives and effects of intermacrocyclic interactions        

            T. Guchhait, S. Sasmal, F. S. T. Khan and S. P. Rath *

            Coord. Chem. Rev. 2017, 337, 112-144.  Full Article

The fascinating chemistry of the oxo and hydroxo-bridged diheme centers, covalently connected through bridges varying in lengths and flexibility, has attracted much attention in recent times and a comprehensive review on their syntheses, structures and spectral properties is presented here.


89.    A Tunable Cyclic Container: Guest-Induced Conformational Switching, Efficient Guest Exchange and Selective Isolation of C70 from Fullerene Mixture

           P. Mondal and S. P. Rath*

          Chem. Asian J. 2017, 12, 1824-1835. Full Article

A tunable cyclic porphyrin dimer, 1 has been employed for efficient encapsulation and selective exchange of aromatic guests (TCNQ/C60/C70) by adjusting its conformation. Moreover, a high binding affinity of the cyclic dimer towards C70 over C60 allows easy extraction and efficient isolation of C70 from a C60/C70 fullerene mixture.


88.  Metal-Centre-Driven Supramolecular Chirogenesis in Tweezer Amino Alcohol Complexes: Structural, Spectroscopic and Theoretical Investigations

         A. Dhamija, B. Saha and S. P. Rath*

          Inorg. Chem. 2017, 56, ASAP. Full Article

A dibenzothiophene-bridged Zn(II)/Mg(II)bisporphyrin host have been utilized for direct determination of absolute stereochemistry of a series of aminoalcohols. Experimental and DFT calculations have rationalized the role of various geometrical conformers and metal ions therein in the chirality induction processes.


87.  Complexation of Chiral Zinc-Porphyrin Tweezer with Achiral Diamines: Induction and Two-Step Inversion of Interporphyrin Helicity Monitored by ECD

          B. Saha, Sk. A. Ikbal, A. Petrovic, N. Berova* and S. P. Rath*

          Inorg. Chem. 2017, 56, 3849-3860. Full Article

A new chiral Zn(II) bisporphyrin tweezer 1 is synthesized; blue-line shows its CD and UV-vis spectra. Addition of achiral guests such as 1,5-diamino pentane to 1 invert the sign of CD exciton couplet to form 1:1 sandwich complex 1•L (red-line) in its low concentration. Further additions of guest result in second inversion due to the formation of 1:2 open complex 1•(L)2 (green-line).


86.    Oxidation Triggers Extensive Conjugation and Unusual Stabilization of Two Di-heme Dication Diradical Intermediates: Role of Bridging Group for Electronic Communication

          D. Sil, S. Dey, A. Kumar, S. Bhowmik and S. P. Rath*

          Chem. Sci. 2016, 7, 1212-1223.  Full Article (Edge Article)

Unlike bis-Fe(IV) state in MauG, the 2e-oxidation has stabilized two ferric hemes, each coupled with a porphyrin cation radical. The extensive π-conjugation enables the generation of a charge resonance band ~1200 nm and allows antiferromagnetic coupling between iron and porphyrin radical spins of both rings.


85.    A Highly Oxidized Cobalt Porphyrin Dimer: Spin Coupling and Stabilization of the Four-Electron Oxidation Product

          S. Dey, D. Sil and S. P. Rath*

          Angew. Chem. Int. Ed. 2016, 55, 996-1000. Full Article

Four to be sure: The oxidation of a cobalt(II) porphyrin dimer with iodine readily produced a cobalt(III) porphyrin π-cation radical dimer. Extensive π conjugation through the ethylene bridge led to several unusual spectral and geometrical features of this four-electron oxidized complex and stabilized the singlet state by enabling strong antiferromagnetic coupling between the π-cation radicals.


84.    Hydrogen Bonding Interactions Trigger a Spin-Flip in Iron(III)-Porphyrin Complexes

          D. Sahoo, M. G. Quesne, S. P. de Visser* and S. P. Rath*

          Angew. Chem. Int. Ed. 2015, 54, 4796-4800. Full Article

Spin control: The electronic structure of a five-coordinate iron(III) porphinato chloride has been found to depend on the presence of hydrogen-bonding interactions, with the iron center switching reversibly between a high (S=5/2) and intermediate spin (S=3/2) state. Computational calculations clearly support the experimentally assigned spin state.


83.    A Nonempirical Approach for Direct Determination of the Absolute Configuration of 1,2-Diols and Amino Alcohols using Mg(II)bisporphyrin

           Sk. A. Ikbal, A. Dhamija, S. Brahma and S. P. Rath*

           J. Org. Chem. 2016, 81, 5440-5449. Full Article

A simple, facile and direct protocol to determine the absolute stereochemistry of a variety of chiral 1,2-diol/amino alcohol at room temperature has been reported. The sign of the CD couplet has also been found inverted on moving the stereogenic centre by one C-atom simply from the bound to an unbound functionality and thus able to discriminate between them.



82.    Remarkable Anion Dependent Spin state Switching in Diiron(III)-μ-Hydroxo Bisporphyrins: What role do Counter ions play?

          F. S. T. Khan, A. K. Pandey and S. P. Rath*

          Chem. Eur. J. 2016, 22, 16124-16137. Full Article

 

All about the spin: The possible roles of the counter ion in controlling the spin state of iron in μ-hydroxo bisporphyrins are demonstrated. The counter ion has been shown to perturb the spin-state ordering through, for example, hydrogen-bonding interactions, switching between counter ion and axial ligand positions, ion-pair interactions, and charge polarization.


81.    Effect of Inter-porphyrin Distance on Spin-state in Diiron(III) μ-Hydroxo Bisporphyrins

          D. Sil, F. S. T. Khan and S. P. Rath*

          Chem. Eur. J. 2016, 22, 14585-14597. Full Article

Spot the difference: A series of diethyl pyrrole-bridged diiron(III) μ-hydroxo bisporphyrins that stabilize two equivalent iron(III) centers, unlike previously reported ethane-bridged analogues, are reported. Experimental evidence and DFT calculations indicate the increased inter-porphyrin distance in the diethyl pyrrole-bridged complexes as a factor for rendering the two iron(III) centers equivalent.


80.    Diiron(III)-μ-Fluoro Bisporphyrins: Effect of Bridging Ligand on the Metal Spin State

          D. Sil, A. Kumar and S. P. Rath*

          Chem. Eur. J. 2016, 22, 11214-11223. Full Article [Highlighted as Frontispiece (Hot Paper)]

 

Metalloporphyrins: A hitherto unknown family of diiron(III)-μ-fluoro bisporphyrins have been synthesized and structurally characterized, for the first time.


79.    Cyclic Zn(II)bisporphyrin Based Molecular Switch: Supramolecular Control of Complexation Mediated Conformational Switching and Photoinduced Electron Transfer

          P. Mondal and S. P. Rath*

          Chem. Eur. J. 2016, 22, 5607-5619. Full Article

Molecular switch: A cyclic zinc(II) bisporphyrin was employed as an efficient molecular switch under the regulation of π-acceptors and bidentate guests, which ultimately control the molecular orientation and charge-transfer process. During the process, two porphyrin rings also reversibly change their relative orientation between perpendicular and parallel.


78.    Induction and Rationalization of Supramolecular Chirality in the Tweezer-diamine Complexes: Insights from Experimental and DFT Studies

         A. Dhamija, Sk. A. Ikbal and S. P. Rath*

          Inorg. Chem. 2016, 55, 13014-13026. Full Article

A series of supramolecular chiral 1:1 sandwich complexes consisting of diphenylether/ethane bridged metallo-bisporphyrin host and chiral diamine guest (L) have been reported. Experimental and DFT calculations have demonstrated the possible interconversion between clockwise (steric-controlled) and anticlockwise (chirality-controlled) twisted conformers just upon changing the bulk of the substituent irrespective of the nature of chirality at the stereogenic centre.


77.    Experimental and Theoretical Investigation on a Series of Novel Dimanganese(III)-μ-hydroxo Bisporphyrins: Magneto-Structural Correlation and Effect of Metal Spin on Porphyrin Core Deformation

             D. Sil, S. Bhowmik, F. S. T. Khan and S. P. Rath*

             Inorg. Chem. 2016, 55, 3239-3251. Full Article

A hitherto unknown family of remarkably bent dimanganese(III)-μ-hydroxo bisporphyrin with different counter anions have been reported here. Unlike its diiron analog, two equivalent high-spin manganese(III) centers with equally distorted porphyrin rings are observed in the complexes.


76.    Effect of Two Interacting Rings in Metalloporphyrin Dimers upon Stepwise Oxidation

         S. Dey, D. Sil, Y. A. Pandit and S. P. Rath*

          Inorg. Chem. 2016, 55, 3229-3238. Full Article

2e-oxidation of ethylene-bridged metalloporphyrin dimers (M: 2H, Zn2+) result in the formation of dication diradical complexes in which the cis isomer converts to trans. Structural and spectroscopic investigations have revealed strong electronic communications between two porphyrin π-cation radicals through the bridge which also allows strong antiferromagnetic coupling between the radical spins to form diamagnetic complexes.


75.    Binuclear Highly distorted Iron(III) Porphyrins Bridged by the Dianions of Hydroquinones: Role of Bridge in the Electronic Communication

           D. Sahoo, A. K. Singh and S. P. Rath*

            Eur. J. Inorg. Chem. 2016, 3305–3313. Full Article

       

A family of binuclear highly substituted and distorted ferric porphyrins bridged through a variety of p-hydroquinone dianions is reported. The iron centres are involved in weak antiferromagnetic exchange interactions, the extent of which depends on the electronic nature of the bridge.


74.    Spin Modulation in Highly Distorted Fe(III) Porphyrinates Using Axial Coordination and their π-Cation Radicals

         D. Sahoo, T. Guchhait and S. P. Rath*

          Eur. J. Inorg. Chem. 2016, 3441–3453. Full Article

     

A series of five-coordinate Fe(III)octaaryltetraphenylporphyrins varying axial ligand field strength and their 1e-oxidized complex have been synthesized and characterized. The molecular structures and their spectroscopic properties including metal spins have been scrutinized.


73.    An Ethane-bridged Porphyrin Dimer as Model of Di-heme Proteins: Inorganic and Bioinorganic Perspectives and Consequences of Heme-Heme Interactions

          D. Sil and S. P. Rath*

          Dalton Trans. 2015, 44, 16195-16211.  Full Article (Invited Perspective Article)

A brief account of our recent efforts on how inter-heme interactions can possibly change the structure and functional properties of the individual heme centers in a highly flexible ethane-bridged porphyrin dimer has been presented.


72.    Controlled generation of highly saddled (porphyrinato) iron(III) iodide, tri-iodide and one-electron oxidized complex

          D. Sahoo and S. P. Rath*

          Chem. Commun. 2015, 51, 16790-16793. Full Article

Three iron(III) porphyrinato complexes have been isolated selectively just by varying iodine concentration which eventually form admixed-intermediate (iodo complex), pure intermediate (tri-iodide complex) and high-spin (1e-oxidized complex) states of iron where iodide and/or tri-iodide used as axial ligands. Computational calculations clearly support the experimentally assigned spin state.


71.    Metal-coordination-driven Mixed Ligand Binding in Supramolecular Bisporphyrin Tweezers

          Sk. A. Ikbal, A. Dhamija and S. P. Rath*

          Chem. Commun. 2015, 51, 14107-14110. Full Article

The mixed ligand polymers of Mg(II)bisporphyrin with heterogeneous guest pairs have been synthesized just by mixing host and guests in one pot and structurally characterized. The guest ligands are bound selectively between inside and outside the bisporphyrin cavity.


70.    Step-wise induction, amplification and inversion of molecular chirality through the coordination of chiral diamines with Zn(II)bisporphyrin

          Sk. A. Ikbal, S. Brahma and S. P. Rath*

          Chem. Commun. 2015, 51, 895-898. Full Article

A clear structural rationalization of the origin of chirality transfer from an optically active diamine guest to an achiral Zn(II)bisporphyrin host in a 1:1 and 2:3 host-guest supramolecular complex has been demonstrated for the first time. During the process, chirality inversion along with amplification was observed.


69.    Stoichiometry-controlled supramolecular chirality induction in magnesium (II) porphyrin dimer by amino alcohols: mechanistic insights and effect of ligand bulkiness

          S. A. Ikbal, B. Saha and S. P. Rath*

          J. Indian Chem. Soc. 2015, 92, 2001-2014. (Invited article in a special issue of the Journal of Indian Chemical Society on the occasion of 80th birthday of Prof. Animesh Chakravorty)


68.    Highly selective and sensitive detection of picric acid explosive by a bisporphyrin cleft: synergistic effects of encapsulation, efficient electron transfer, and hydrogen bonding

          P. Mondal and S. P. Rath*

          Eur. J. Inorg. Chem. 2015, 4956-4964. Full Article

An efficient host–guest complexation leads to rapid, highly selective, and efficient detection of picric acid (PA) in the presence of other nitroaromatics in solution as well as in the solid phase.


67.    Spin state ordering in hydroxo bridged diiron(III)bisporphyrin complexes

          M. A. Sainna, D. Sil, D. Sahoo, B. Martin, S. P. Rath,* P. Comba* and S. P. de Visser*

          Inorg. Chem. 2015, 54, 1919-1930. Full Article

We report the synthesis, structure, and spectroscopic characterization of 1,2-bis[μ-hydroxo iron(III) 5-(2,3,7,8,12,13,17,18-octaethylporphyrinyl)]ethane with PF6 and SbF6counteranions. The two iron centers are nonequivalent with admixed intermediate spin state (S = 3/2 with a minor contribution of S = 5/2) on each metal both in the solid and in solution. The molecules are compared with previously known μ-hydroxo complexes with other counterions, such as I3, BF4, and ClO4, which demonstrates that the nature of the counterion can affect the spin-state ordering dramatically.


66.    Aggregation-controlled excimer emission in an axial anthracene–Sn(IV)porphyrin–anthracene triad in the solid and solution phases

          S. Dey, P. Mondal and S. P. Rath*

          New J. Chem. 2015, 39, 4100-4108. Full Article (Invited article)

An anthracene-porphyrin donor-acceptor triad has been synthesized and its photophysical properties along with excimer behavior are investigated.


65.    Efficient Host-Guest Complexation of a Bisporphyrin Host with Electron Deficient Guests: Synthesis, Structure and Photoinduced Electron Transfer

          P. Mondal and S. P. Rath*

          Isr. J. Chem. 2016, 56, 144-155. Full Article (Invited article in a special issue on "Porphyrins and Porphyrinoids")


64.    Axial Thiophenolate Coordination on Diiron(III)bisporphyrin: Influence of Heme-Heme Interactions on Structure, Function and Electrochemical Properties of the Individual Heme Center

          D. Sil, F. S. T. Khan and S. P. Rath*

          Inorg. Chem. 2014, 53, 11925-11936. Full Article

Synthesis, X-ray structures and properties of a series of diiron(III)bisporphyrin with axial thiophenolate coordination has been reported. The large difference in chemical and electrochemical properties of the dihemes as compared to the monoheme analogs provide an unequivocal evidence of the role played by inter-heme interactions.


63.    Transfer and Control of Molecular Chirality in the 1:2 Host-Guest Supramolecular Complex Consisting of Mg(II) bisporphyrin and Chiral Diols: Effect of H-bonding on Rationalization of Chirality

          Sk. A. Ikbal, S. Brahma and S. P. Rath*

          Chem. Commun. 2014, 50, 14037-14040. Full Article

Chiral diol substrate binds to Mg(II)bisporphyrin in an unusual endo-endo fashion due to inter- ligand H-bonding which eventually results in remarkably high amplitude bisignate CD signal.


62.   Highly Enhanced Bisignate Circular Dichroism of Ferrocene-Bridged Zn(II) Bisporphyrin Tweezer with Extended Chiral Substrates due to Well-matched Host-Guest System

          S. Brahma, Sk. A. Ikbal, A. Dhamija and S. P. Rath*

          Inorg. Chem. 201453, 2381-2395. Full Article

    

Four new supramolecular chiral tweezer-diamine complexes consisting of an achiral Zn(II)bisporhyrin host (green line) and two small chiral diamines, (1R,2R)-DPEA and (1S,2S)-CHDA, and two large extended chiral diamines, (1R,2R)-DPEApy and (1S,2S)-CHDApy, are reported. Complexes with extended chiral substrates show remarkably high amplitude of bisignate CD signal (blue-line) while smaller substrates show low value (red-line) with opposite sign of CD couplet.


61.    Synthesis, Structure, and Properties of a Series of Chiral Tweezer-Diamine Complexes Consisting of an Achiral Zinc(II) Bisporphyrin Host and Chiral Diamine Guest: Induction and Rationalization of Supramolecular Chirality

          S. Brahma, Sk. A. Ikbal and S. P. Rath*

          Inorg. Chem. 2014, 53, 49-62. Full Article

A series of supramolecular chiral tweezers consisting of an achiral Zn(II)bisporphyrin host and variety of chiral diamine guests have been presented here which demonstrates a full and unambiguous rationalization of the chirality transfer process from the chiral guest to the achiral host observed in many natural and artificial supramolecular assemblies.


60.   Syn-Anti  Conformational Switching in an Ethane-bridged Co(II)bisporphyrin Induced by External Stimuli: Effects of Inter-macrocyclic Interactions, Axial Ligation and Chemical and Electrochemical Oxidations

          S. Dey and S. P. Rath*

          Dalton Trans. 201443, 2301-2314.  Full Article

The reversible syn-anti conformational switching has been observed either by various external ligands or stepwise oxidations.


59.    Iron(III) and Copper(II) complexes of trans-bis(ferrocenyl)porphyrin: effect of metal ions on long-range electronic communication

           D. Sahoo and S. P. Rath*

           J. Chem. Sci. 2014127, 327.  (Invited article in a Special Issue on MTIC-XV)


58.    Building-up Novel Coordination Polymer with Zn(II) Porphyrin Dimer: Synthesis, Structures, Surface Morphology and Effect of Axial Ligands

          Sk. A. Ikbal, S. Brahma, A. Dhamija and S. P. Rath*

          J. Chem. Sci. 2014, 126, 1451.  (Invited article in the special issue on "Chemical Crystallography")


57.    Unusual Stabilization of an Intermediate Spin of Iron upon Axial Phenoxide Coordination on a Diiron(III)bisporphyrin: Effect of Heme-Heme Interactions

           S. Bhowmik, S. Dey and S. P. Rath*

           Chem. Eur. J. 2013, 19, 13732-13744. Full Article

Spin city: Five new phenolate complexes of diiron(III)bisporphyrin, in which 2,4,6-trinitrophenol stabilizes the pure intermediate-spin state (S=3/2) of iron, are reported for the first time. Similar coordination with the corresponding FeIII monoporphyrin only resulted in stabilization of the high-spin state.


56.    Self-assembly of Cobalt(II) and Zinc(II) Tetranitro Octaethylporphyrin via Bidentate Axial Ligands: Synthesis, Structure, Surface Morphology and Effect of Axial Coordination

          S. Dey, Sk A. Ikbal and S. P. Rath*

          New J. Chem. 2013, 37, 1458-1470.(Invited article)


55.    Effect of Heme-Heme Interactions and Modulation of Metal Spins by Counter Anions in a Series of Diiron(III)-μ-hydroxo Bisporphyrins: Unusual Stabilization of Two Different Spins in a Single Molecular Framework

          S. K. Ghosh, S. Bhowmik and S. P. Rath*

          Chem. Eur. J. 201319, 17846-17859. Full Article

Anion effect on diiron-bisporphyrin properties: A new family of five ethene-bridged diiron(III)-μ-hydroxo bisporphyrins with the same core structure but different counter anions is reported herein. In these complexes, two different spin states of Fe are stabilized in a single molecular framework.


54.   Supramolecular BODIPY-Zn(II)-Bisporphyrin Dyad and Trinitrofluorenone Encapsulated Triad as Models of Antenna-reaction Center: Synthesis, Structure and Photophysical Properties

          P. Mondal, A. Chaudhary and S. P. Rath*

          Dalton Trans. 201342, 12381-12394. Full Article

We describe the synthesis, characterization and photophysical properties of the dyads Zn2DEP·TNF (1) and Zn2DEP·2Py-BDP (2) and triad Zn2DEP·2Py-BDP·TNF (3), which enable us to investigate the changes in the spectroscopic properties upon the axial coordination of 2DEP in the dyads and the further encapsulation of TNF in the triad.


53.   Formation of exo-exo, exo-endo and tweezer conformation induced by axial ligand in a Zn(II) bisporphyrin: Synthesis, structure and property

          A. Chaudhary, Sk. A. Ikbal, S. Brahma and S. P. Rath*

          Polyhedron 2013, 52, 761-769.  Full Article (Invited article in a special volume dedicated to Alfred Werner on the 100th Anniversary of his Nobel Prize in Chemistry in 1913)

A detailed structural and spectroscopic investigation of axial ligand coordination on Zinc(II)pyrrole-bridged bisporphyrin (Zn2DEP), have been reported. Our findings demonstrate that the DEP system provides a Pacman pocket with very high vertical and horizontal flexibility that leads to the formation of exo-endo, exo-exo and tweezer complexes of Zn(II)(bisporphyrinato), for the first time in the solid state, depending upon the size and type of axial ligands used.


52.    Switching Orientation of Two Axial Imidazole Ligands between Parallel and Perpendicular in Low-Spin Fe(III) and Fe(II) Nonplanar Porphyrinates

          R. Patra, D. Sahoo, S. Dey, D. Sil and S. P. Rath*

          Inorg. Chem. 2012, 51, 11294-11305. Full Article

Bis-imidazole-coordinated Fe(III) and Fe(II) porphyrin changes the axial ligand orientation from parallel to perpendicular, respectively, in a nonplanar porphyrinic environment.


51.   Building-up Remarkably Stable Magnesium Porphyrin Polymers Self-assembled via Bidentate Axial Ligands: Synthesis, Structure, Surface Morphology and Effect of Bridging Ligands

          Sk. A. Ikbal, S. Brahma and S. P. Rath*

          Inorg. Chem. 2012, 51, 9666-9676.  Full Article

A series of remarkably stable magnesium porphyrin polymers bridged by large bidentate axial ligands, have been synthesized in one pot in excellent yields and structurally characterized. The surface patterns on HOPG have also been investigated.


50.    Protonation of an oxo-Bridged Diiron Unit Makes Two Iron Centers Different: A New Class of Diiron(III)-μ-hydroxo Bisporphyrin and Control of Spins by Counter Anions

          S. Bhowmik, S. K. Ghosh and S. P. Rath*

          Chem. Eur. J. 2012, 18, 13025-13037.  Full Article

The core of the matter: A previously unknown family of diiron(III)-μ-hydroxo bisporphyrins in which two different spin states of Fe are stabilized in a single molecular framework, even though both cores have identical molecular structures, is presented. The spin states were found to be dependent on the counterion.


49.    Induction of Supramolecular Chirality in Di-Zinc(II) Bisporphyrin via Tweezer Formation: Synthesis, Structure and Rationalization of Chirality

           S. Brahma, Sk. A. Ikbal, S. Dey and S. P. Rath*

          Chem. Commun. 2012, 48, 4070-4072.   Full Article (Invited article in a special thematic issue 'Porphyrins and Phthalocyanines')

Two new supramolecular complexes consisting of an achiral bisporphyrin host and a chiral diamine guest are reported. One shows remarkably high amplitude of bisignate CD signal while other one shows very low value.


48.   Encapsulation of TCNQ and Acridinium Ion within Bisporphyrin Cavity: Synthesis, Structure, Photophysical and HOMO-LUMO Gap Mediated Electron Transfer Properties

          A. Chaudhary and S. P. Rath*

          Chem. Eur. J. 2012, 18, 7404-7417. Full Article

Donor-acceptor complexes: Donor–acceptor complexes, which were constructed from free base bisporphyrin (H4DEP) as a host, strongly encapsulated two electron-deficient guests, TCNQ and the acridinium ion, in its clefts. The extremely low electrochemically evaluated HOMO–LUMO gap in H4DEP•TCNQ led to facile electron transfer from the host to the guest at room temperature, whilst partial electron transfer took place in [H4DEP•AcH]ClO4.


47.    Efficient Complexation of Pyrrole-bridged Di-Zinc(II) Bisporphyrin with Fluorescent Probe Pyrene: Synthesis, Structure, and Photoinduced Singlet-Singlet Energy Transfer

          A. Chaudhary and S. P. Rath*

          Chem. Eur. J. 2011, 17, 11478-11487. Full Article

Fluoroscent guest! : A dizinc(II) bisporphyrin encapsulates the fluorescent probe pyrene (guest) within the bisporphyrin clefts. The solid-state assembly is very robust in solution for days. Spectroscopic studies indicate significant photoinduced singlet–singlet energy transformation from guest to host.


46.     Magnesium inserted porphyrin compound, its blends and devices thereof

           S. S. K. Iyer, S. P. Rath, A. Singh and Sk. A. Ikbal

           Patent Application No.  3272/DEL/2011 dated November 17, 2011.


45.    Control of Spins by Ring Deformation in a Diiron(III)bisporphyrin: Reversal of ClO4- and CF3SO3- Ligand Field Strength on the Magnetochemical Series

          S. Bhowmik, S. K. Ghosh and S. P. Rath*

          Chem. Commun. 201147, 4790-4792. Full Article

The complete reversal of the ligand field strength between ClO4- and CF3SO3- on the ‘magnetochemical’ series is observed in a diiron(III)bisporphyrin. While ClO4- gives typical high-spin complex, just by twisting the conformation of the macrocycle shows properties with pure intermediate-spin state with CF3SO3- although the axial ligand strengths suggest the reverse order of spin stabilization.


44.    Axial Phenoxide Coordination on Di-Iron(III)bisporphyrin: Insights from Experimental and DFT Studies

         S. Bhowmik, D. Sil, R. Patra and S. P. Rath*

         J. Chem. Sci. 2011, 123, 827. (Invited article in the Special Issue of International Year  of Chemistry)


43.    Syn-anti Conformational Switching: Synthesis and X-ray Structures of Tweezer and Anti Form in a Zinc Porphyrin Dimer Induced by Axial Ligands

          S. Brahma, Sk. A. Ikbal and S. P. Rath*

          Inorg. Chim. Acta. 2011, 372, 62-70. Full Article (Invited article in the Special Volume dedicated to Professor S. S. Krishnamurthy on the occasion of his 70th birth anniversary)


42.    Models for the Photosynthetic Reaction Center: Synthesis, Structure, and Electrochemical Properties of a Cofacial Di-palladium Bisporphyrin

          A. Chaudhary, R. Patra and S. P. Rath*

          Indian J. Chem., Sec. A. 201150, 1436. (Invited article in the Special Issue dedicated to Acharya Prafulla Chandra Ray on the occasion of his 150th birth anniversary).


41.     Synthesis, Structure and Properties of a High-Spin Fe(III) Porphyrin with Nonequivalent Axial Ligands: Implications for the Hemoproteins

           A. Chaudhary, R. Patra, and S. P. Rath*

           Indian J. Chem., Sec. A. 2011, 432.  (Invited article in the Special Issue on Bioinorganic Chemistry dedicated to Professor S. Mitra on the occasion of his 70th birth anniversary).


40.     A Remarkably Bent Diiron(III)-μ-Hydroxo Bisporphyrin: Unusual Stabilization of Two Spin States of Iron in a Single Molecular Framework

           S. K. Ghosh and S. P. Rath*

           J. Am. Chem. Soc. 2010, 132, 17983-17985. Full Article

A novel diiron(III) bisporphyrin bridged by a single hydroxo group between two Fe-centers is reported in which the Fe-O(H)-Fe angle becomes the smallest ever reported in a Fe-porphyrin and two different spin states of Fe are stabilized in a single molecular framework, for the first time, although both cores have exactly the same chemical entity.


39.     Binding of Catechols to Iron(III) Octaethyl Porphyrin: An Experimental and DFT Investigation

           A. Chaudhury, R. Patra and S. P. Rath*

           Eur. J. Inorg. Chem. 2010, 5211-5221. Full Article

The synthesis, X-ray structures, and properties of new heme analogues FeIII(OEP)(L) (L: Hcat, 4-NO2-Hcat, 4-tBu-Hcat, and sal) are reported, in which catechol binds in an η1-fashion as an axialligand. Spectroelectrochemical studies of one- and two-electron oxidations are also reported. Experimental findings are supported by DFT calculations.


38.     Effects of Axial Pyridine Coordination in a Saddle-Distorted Porphyrin macrocycle: Stabilization of Hexa-coordinated High-Spin Fe(III) and Air-stable Low-Spin Iron(II) Porphyrinates

            R. Patra, S. Bhowmik, S. K. Ghosh and S. P. Rath*

            Dalton Trans. 2010, 39, 5795-5806. Full Article

We have reported here the effect of axial ligand L (L: pyridine/substituted pyridine) on FeIII(tn-OEP)Cl/FeIII(tn-OEP)ClO4 that first form high-spin FeIII(tn-OEP)(L)2.X (X: Cl, ClO4) which, on longer exposure, spontaneously auto reduce to a series of air stable FeII(tn-OEP)(L)2 complexes.


37.      Synthesis, Structure and Photocatalytic Activity of a Remarkably Bent, Cofacial Ethene-linked Diiron(III) μ-oxobisporphyrin

            S. K. Ghosh, R. Patra and S. P. Rath*

            Inorg. Chim. Acta. 2010, 363, 2791-2799. Full Article (Invited article in the Special Volume dedicated to Professor A. Chakravorty on the  occasion of his 75th birth anniversary)

A remarkably bent diFe(III)-μ-oxo bisporphyrin with Fe-O-Fe angles of 150.9(2)° is reported in which the bisporphyrin platform ‘open’ and ‘close’ its binding pockets reversibly with very high vertical flexibility. The complex is thermally very inert but undergo prompt photocatalytic oxidation when photolyzed with excess phosphites in benzene under mild condition using aerial oxygen.


36.      Synthesis and Characterization of anti-bisFe(III) Porphyrins, syn-bisFe(III)-μ-oxo Porphyrin and syn-bisFe(III)-μ-oxo Porphyrin Cation Radical

             S. K. Ghosh, R. Patra and S. P. Rath*

             Inorg. Chem. 201049, 3449-3460. Full Article

BisFe(III) porphyrins containing highly flexible ethane linker are reported in which the bisporphyrin platform ‘open’ and ‘close’ its binding pockets leading to facile syn-anti conformational switching with very high vertical flexibility in a single molecular framework.


35.     Axial Ligand Orientations in a Distorted Porphyrin Macrocycle: Synthesis, Structure and Properties of Low-Spin bis (Imidazole) Fe(III) and Fe(II) porphyrinates

            R. Patra, A. Chaudhary, S. K. Ghosh and S. P. Rath*

            Inorg. Chem. 2010, 49, 2057-2067. Full Article

 

Iron(II) and iron(III) tetranitrooctaethylporphyrinates coordinated with two planar and unhindered imidazoles as axial ligand have nearly perpendicular and parallel orientation preferences, respectively, in a nonplanar porphyrinic environment.


34.     Cyanide binding to iron in a highly distorted porphyrin macrocycle: Synthesis and structure of low-spin Fe(II) dicyano porphyrin

            R. Patra and S. P. Rath*

            Inorg. Chem. Commun. 2009, 515-519. Full Article

[K(18-crown-6)(H2O)2]2[FeII(tn-OEP)(CN)2] represents the first structurally characterized Fe(II) dicyano porphyrins in a highly distorted macocyclic environment. The metal iron is on the plane of the four porphyrinic nitrogens which are accompanied by the decrease of the saddle distortion with a clear and significant increase in ruffling.


33.      The Effect of Steric Crowding on Porphyrin Conformation and Ring Orientations in a Series of Iron(III) μ-Oxo Dimers Containing meso-Nitrooctaethylporphyrins

            R. Patra, S. Bhowmik, S. K. Ghosh and S. P. Rath

            Eur. J. Inorg. Chem. 2009, 5, 654-665. Full Article

The structural and electronic effects of the progressive addition of bulky and electron-withdrawing NO2 groups at the adjacent meso carbon positions of FeIII-μ-oxo octaethylporphyrin dimers are examined.


32.     Modulation of  metal displacement in a saddle distorted  macrocycle: synthesis, structure and properties of high spin Fe(III) porphyrins and implications for the hemoprotiens

            R. Patra, A. Chaudhary, S. K. Ghosh and S. P. Rath*

            Inorg. Chem. 2008, 47, 8324-8335. Full Article

A rare family of five and six-coordinated high-spin Fe(III) porphyrins incorporating weak axial ligands are synthesized and structurally characterized which demonstrates, for the first time, step-wise metal displacements in a single distorted macrocyclic environment that has generally been seen in many biological systems.


31. Remarkably Bent, Ethane-Linked, Diiron(III) μ-Oxobisporphyrin: Synthesis, Structure, Conformational Switching, and Photocatalytic Oxidation

          S. K. Ghosh, R. Patra and S. P. Rath*

          Inorg. Chem. 2008, 47, 10196-10198. Full Article

A remarkably bent bisFe(III)-μ-oxo porphyrin with Fe-O-Fe angles of 147.9(1)º containing highly flexible ethane linker is reported which authenticates, for the first time, the unprecedented ability of the bisporphyrin platform to ‘open’ and ‘close’ its binding pockets leading to facile syn-anti conformational switching with very high vertical flexibility of over 6.5Å in a single molecular framework.


30.   Axial Ligand Coordination in Sterically Strained Vanadyl  Porphyrins: Synthesis, Structure, and Properties

             S. K. Ghosh, R. Patra and S. P. Rath*

             Inorg. Chem. 2008, 47, 9848-9856. Full Article

A hitherto unknown family of six-coordinate vanadyl porphyrins of the sterically crowded, nonplanar 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetranitroporphyrin incorporating axial ligand L (L: pyridine, THF and MeOH), have been isolated as VO(tn-OEP)(L) in the solid phase for the first time and structurally characterized as shown.


29.      Electronic Structure of the Glyoxalbis(2-hydroxyanil) (gha) Ligand in [CoIII(gha)(PPh3)2]+: Radical vs. Non-radical States

            A. S. Roy, N. Muresan, H. M. Tuononen, S. P. Rath, P. Ghosh

            Dalton Trans. 2008, 26, 3438.


28.     First Ruthenium Complex of Glyoxalbis(N-phenyl)osazone (LNHPhH2): Synthesis, X-ray Structure, Spectra, and Density Functional Theory Calculations of (LNHPhH2)Ru(PPh3)2Cl2

             A. S. Roy, H. M. Tuononen, S. P. Rath, P. Ghosh

             Inorg. Chem. 2007, 46, 5942.


27.     Dioxygen Reactivity of Meso-hydroxylated Hemes: Intermediates in Heme Degradation  Process Catalyzed by Heme-oxygenase.

              S. P. Rath*

              J. Chem. Sci. 2006, 118, 463.


26.      Electron Distribution in Octaethyloxophlorin Complexes. Importance of the Fe(III) Oxophlorin Trianion Form in the Bis-pyridine and Bis-imidazole Complexes

             S. P. Rath, M. M. Olmstead and A. L. Balch

             Inorg. Chem. 2006, 45, 6083.


25.     Metal Complexes of meso-Amino-octaethylporphyrin and the Oxidation of Ni(II)(meso-amino-octaethylporphyrin)

             N. Sprutta, S. P. Rath, M. M. Olmstead and A. L. Balch

             Inorg. Chem. 2005, 44, 1452.


24.       Pyramidalization of Gd3N inside a C80 Cage. The Synthesis and Structure of Gd3N@C80

             S. Stevenson, J. P. Stevenson, J. E. Reid, M. M. Olmstead, S. P. Rath and A. L. Balch

             Chem. Commun. 2004, 2814.


23.      Oxidative Verdoheme Formation and Stabilization by Axial Isocyanide Ligation

            S. P. Rath, M. M. Olmstead and A. L. Balch

            Inorg. Chem. 200443, 7648.


22.     Reaction of Meso-hydroxyhemes with Carbon Monoxide and Reducing Agents in Search  of the Elusive Species Responsible for the g=2.006 Resonance of Carbon Monoxide Treated Heme Oxygenase. Isolation of Diamagnetic Iron(II) Complexes of Octaethyl meso-hydroxyporphyrin

            S. P. Rath, M. M. Olmstead and A. L. Balch

            Inorg. Chem. 2004, 43, 6357.


21.      Formation of a Highly Oxidized Iron Biliverdin Complex Upon Treatment of a Five-coordinate Verdoheme with Dioxygen

              K. T. Nguyen, S. P. Rath, L. Latos-Grazynski, M. M. Olmstead and A. L. Balch

              J. Am. Chem. Soc. 2004, 126, 6210.


20.      The Effect of Axial Ligands on Spin States and Electron Distribution in Iron Complexes of Octaethyloxophlorin, Intermediates in Heme Degradation

              S. P. Rath, M. M. Olmstead and A. L. Balch

              J. Am. Chem. Soc. 2004, 126, 6379.


19.       A Novel Pentacoordinated Dioxovanadium(V) Salicylaldiminate: Solvent Specific Crystalisation of Dimorphs with Contrasting Coordination Geometries, Ligand Conformations and Supramolecular Architectures 

              B. Baruah, S. P. Rath and A. Chakravorty

              Eur. J. Inorg. Chem. 2004, 1873.


18.       Facile Ring Opening of Iron(III) and Iron (II) Complexes of meso-Amino-octaethylporphyrin by Dioxygen

              S. P. Rath, H. Kalish, L. Latos-Grazynski, M. M. Olmstead and A. L. Balch

               J. Am. Chem. Soc. 2004126, 646.


17.        Formation and Isolation of an Iron-Tripyrrole Complex from Heme Degradation

              S. P. Rath, M. M. Olmstead, L. Latos-Grazynski and A. L. Balch

              J. Am. Chem. Soc. 2003, 125, 12678.


16.       Reversible Binding of Nitric Oxide and Carbon-Carbon Bond Formation in a Meso-Hydroxylated Heme

             S. P. Rath, R. Koerner, M. M. Olmstead and A. L. Balch

              J. Am. Chem. Soc. 2003, 125, 11798.


15.       Heme Cleavage with Remarkable Ease: Paramagnatic Intermediates Formed by Aerial Oxidation of a Meso-Amino-Substituted Iron Porphyrin

             H. Kalish, H. M. Lee, M. M. Olmstead, L. Latos-Grazynski, S. P. Rath and A. L. Balch

              J. Am. Chem. Soc. 2003125, 4674.


14.        Synthesis, structure and properities of mononuclear oxovanadium(V) alkoxides incorporating chelated ethane-1,2-diol and propane-1,3-diol

              K. K. Rajak, S. Mondal and S. P. Rath

              Polyhedron 2000, 19, 931.


13.        Sugar Binding to VO3+. Synthesis and Structure of a New Mannopyranoside Vanadate

              K. K. Rajak, B. Baruah, S. P. Rath and A. Chakravorty

               Inorg. Chem. 2000, 39, 1598.


12.        Ruthenium dithiophosphates: Synthesis, X-ray crystal structure, spectroscopic and electrochemical properties

               P. U. Jain, P. Munshi, M. G. Walawalkar, S. P. Rath, K. K. Rajak and G. K. Lahiri

               Polyhedron 2000, 19, 801.


11.      Synthesis, Structure and Catecholase Reaction of a Vanadate Ester System  Incorporating Monoionized Catechol Chelation

               S. P. Rath, K. K. Rajak and A. Chakravorty

               Inorg. Chem. 199938, 4376.


10.       Carbohydrate Binding to VO3+. Sugar Vanadate Esters Incorporating L-Amino Acid Schiff Bases as Coligands

              K. K. Rajak, S. P. Rath, S. Mondal and A. Chakravorty

              Inorg. Chem. 1999, 38, 3283.


9.        Sugar vanadates: synthesis and characterisation of mannopyranoside and ribofuranoside esters incorporating VO3+

             K. K. Rajak, S. P. Rath, S. Mondal and A. Chakravorty

              J. Chem. Soc., Dalton Trans 1999, 2537.


8.          Sugar vanadates : Synthesis and characterisation of a mannopyranoside ester  incorporating  VO3+

              K. K. Rajak, S. P. Rath, S. Mondal and A. Chakravorty

              Indian J. Chem. 199938A, 405.


7.           A Family of (N-Salicylidene-a-aminoacidato)Vanadate Esters Incorporating Propane-1,3-diol and Glycerol: Synthesis, Structure and Reaction

              S. Mondal, S. P. Rath, K. K. Rajak and A. Chakravorty

              Inorg. Chem. 1998, 37, 1713.


6.          Synthesis and Structure of Vanadate Esters of Glycerol and Propane-1,3-diol

              S. P. Rath, K. K. Rajak, S. Mondal and A. Chakravorty

              J. Chem. Soc., Dalton Trans 1998, 2097.


5.          Chemistry of Hydrazonato Oxovanadium(V) Alkoxides Derived from Dihydric/ Monohydric Alkohols

              S. P. Rath, S. Mondal and A. Chakravorty

               Inorg. Chim. Acta (R. H. Holm Issue) 1997263, 247.


4.          Synthesis, Structure and Metal Redox of Alkoxide Bound Oxovanadium(V) Complexes Incorporating N-salicylidene/N-naphthalidene-a-aminoalcohols

              S. P. Rath, T. Ghosh and S. Mondal

              Polyhedron 1997, 16, 4179.


3.          Chemistry of Oxovanadium(V) Alkoxides: Synthesis and Structure of Mononuclear Complexes Incorporating Ethane-1,2-diol

               S. Mondal, S. P. Rath, S. Dutta and A. Chakravorty

                J. Chem. Soc., Dalton Trans 1996, 99. 


2.           Mixed-Ligand Oxovanadium(V) Complexes Incorporating Bidentate Salicylaldehyde and Tridentate Aldimine Ligands

               S. P. Rath, S. Mondal and T. Ghosh

               Transition Met. Chem. 1996, 21, 309.


1.           Water Soluble Mixed-Ligand Oxovanadium(IV) Complexes of Acetylacetone and Aldimine  Ligands

               S. P. Rath, S. Mondal and T. Ghosh

               Indian J. Chem. 1996, 35A, 527.

 

 
2017