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Nath S, Bhattacharya B, Sarkar U, Singh TS. Solvent Effects on the Photophysical Properties of a Donor-acceptor Based Schiff Base. J Fluoresc 2022; 32:1321-1336. [PMID: 35366165 DOI: 10.1007/s10895-022-02905-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/13/2022] [Indexed: 11/24/2022]
Abstract
In this work, a donor-acceptor substituted aromatic system ((E)-N-((E)-3-(4 (dimethylamino)phenyl) allylidene)-4-(trifluoromethyl) benzenamine (DPATB) has been synthesized and its detailed photophysics of intramolecular charge transfer process have been explored on the basis of steady state absorption, fluorescence and time resolved spectroscopy in combination with density functional theory calculations. Large solvent dependency fluorescence spectral shift and the calculated large excited state dipole moment clearly indicate an efficient charge transfer occurring from the donor group to the acceptor moiety in the excited state. Effect on addition of acid and pH on steady state spectral properties further reveals excited state charge transfer character. Quantum chemical calculations were performed in order to study the conformation and polarity of DPATB at their ground as well as excited electronic states. The HOMO and LUMO molecular orbital pictures are obtained at DFT level using B3LYP functional and 6-311 + g(d,p) basis set which clearly support excited state intramolecular charge transfer process. The molecular electrostatic potential maps for the optimized ground state, donor twisted and acceptor twisted geometry shed insight on the electrostatic potential and charge distribution in a system which gives information about the reacting site of the probe and nature of the reaction. In this work, detailed photophysics of excited state intramolecular charge transfer process in donor-acceptor system (DPATB) was evaluated using steady state and time-resolved fluorescence spectroscopy in combination with density functional theory calculations. Large solvent dependency fluorescence spectral shift and the calculated large excited state dipole moment clearly indicate an efficient charge transfer occurring in DPATB. Molecular orbital pictures as obtained from DFT based computational analysis reveals a significant change in the distribution of electron density upon transition from HOMO to LUMO which confirms an ICT process occurring from the donor group to the acceptor moiety in the excited state.
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Affiliation(s)
- Surjatapa Nath
- Department of Chemistry, Assam University, Silchar, Assam, India
| | | | - Utpal Sarkar
- Department of Physics, Assam University, Silchar, India
| | - T Sanjoy Singh
- Department of Chemistry, Assam University, Silchar, Assam, India.
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2
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Speiser B, Zitzer G. Interactions Between Two Cobalt Salen Centers Bridged by Non‐Conjugated Linkers**. ChemElectroChem 2021. [DOI: 10.1002/celc.202100709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Bernd Speiser
- Universität Tübingen Institut für Organische Chemie Auf der Morgenstelle 18 D-72076 Tübingen Germany
| | - Georg Zitzer
- Universität Tübingen Institut für Organische Chemie Auf der Morgenstelle 18 D-72076 Tübingen Germany
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3
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Wang Z, Mu Y. Chiral salenCo( iii) complexes with bulky substituents as catalysts for stereoselective alternating copolymerization of racemic propylene oxide with carbon dioxide and succinic anhydride. Polym Chem 2021. [DOI: 10.1039/d0py01562h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Stereoregular poly(propylene carbonate)s and poly(propylene succinate-block-carbonate)s were synthesized with new chiral salenCo(iii) catalysts carrying bulky substituents.
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Affiliation(s)
- Zhou Wang
- State Key Laboratory for Supramolecular Structure and Materials
- School of Chemistry
- Jilin University
- Changchun 130012
- P. R. China
| | - Ying Mu
- State Key Laboratory for Supramolecular Structure and Materials
- School of Chemistry
- Jilin University
- Changchun 130012
- P. R. China
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4
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Ambrose K, Robertson KN, Kozak CM. Cobalt amino-bis(phenolate) complexes for coupling and copolymerization of epoxides with carbon dioxide. Dalton Trans 2019; 48:6248-6260. [DOI: 10.1039/c9dt00996e] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Electron-withdrawing groups on phenolate donors enhance polycarbonate production from CO2 and cyclohexene oxide by Co(ii) amino-bis(phenolate) complexes.
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Affiliation(s)
- Kenson Ambrose
- Department of Chemistry
- Memorial University of Newfoundland
- St. John's
- Canada A1B 3X7
| | | | - Christopher M. Kozak
- Department of Chemistry
- Memorial University of Newfoundland
- St. John's
- Canada A1B 3X7
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5
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Bandyopadhyay D, Layek M, Fleck M, Saha R, Rizzoli C. Synthesis, crystal structure and antibacterial activity of azido complexes of cobalt(III) containing heteroaromatic Schiff bases. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2017.02.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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6
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Jadhao M, Meitei OR, Joshi R, Kumar H, Das C, Ghosh SK. ESIPT reaction of potential bioactive heterocyclic Schiff base: Atomic visualization coupled with in vitro spectroscopy. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2016.04.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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7
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DiCiccio AM, Longo JM, Rodríguez-Calero GG, Coates GW. Development of Highly Active and Regioselective Catalysts for the Copolymerization of Epoxides with Cyclic Anhydrides: An Unanticipated Effect of Electronic Variation. J Am Chem Soc 2016; 138:7107-13. [PMID: 27171536 DOI: 10.1021/jacs.6b03113] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Recent developments in polyester synthesis have established several systems based on zinc, chromium, cobalt, and aluminum catalysts for the ring-opening alternating copolymerization of epoxides with cyclic anhydrides. However, to date, regioselective processes for this copolymerization have remained relatively unexplored. Herein we report the development of a highly active, regioselective system for the copolymerization of a variety of terminal epoxides and cyclic anhydrides. Unexpectedly, electron withdrawing substituents on the salen framework resulted in a more redox stable Co(III) species and longer catalyst lifetime. Using enantiopure propylene oxide, we synthesized semicrystalline polyesters via the copolymerization of a range of epoxide/anhydride monomer pairs.
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Affiliation(s)
- Angela M DiCiccio
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853-1301, United States
| | - Julie M Longo
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853-1301, United States
| | - Gabriel G Rodríguez-Calero
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853-1301, United States
| | - Geoffrey W Coates
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853-1301, United States
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8
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Cuesta-Aluja L, Castilla J, Masdeu-Bultó AM. Aluminium salabza complexes for fixation of CO2 to organic carbonates. Dalton Trans 2016; 45:14658-67. [DOI: 10.1039/c6dt01069e] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A highly stable and easy to synthesize aluminium complex bearing a flexible N2O2-donor salabza ligand (N,N′-bis(salicylene)-2-aminobenzylamine) in combination with tetrabutylammonium bromide forms an active binary catalytic system for the cycloaddition of CO2 to epoxides (TOFs 120–3434 h−1) under mild conditions (10 bar, 80 °C) and low catalyst loadings (0.05–0.2 mol%).
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Affiliation(s)
- L. Cuesta-Aluja
- Department of Physical and Inorganic Chemistry
- University Rovira i Virgili
- Marcel·lí Domingo
- s/n. 43007 Tarragona
- Spain
| | - J. Castilla
- Department of Physical and Inorganic Chemistry
- University Rovira i Virgili
- Marcel·lí Domingo
- s/n. 43007 Tarragona
- Spain
| | - A. M. Masdeu-Bultó
- Department of Physical and Inorganic Chemistry
- University Rovira i Virgili
- Marcel·lí Domingo
- s/n. 43007 Tarragona
- Spain
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9
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Offermans WK, Bizzarri C, Leitner W, Müller TE. Surprisingly facile CO2 insertion into cobalt alkoxide bonds: A theoretical investigation. Beilstein J Org Chem 2015; 11:1340-51. [PMID: 26425188 PMCID: PMC4578342 DOI: 10.3762/bjoc.11.144] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Accepted: 07/10/2015] [Indexed: 01/26/2023] Open
Abstract
Exploiting carbon dioxide as co-monomer with epoxides in the production of polycarbonates is economically highly attractive. More effective catalysts for this reaction are intensively being sought. To promote better understanding of the catalytic pathways, this study uses density functional theory calculations to elucidate the reaction step of CO2 insertion into cobalt(III)-alkoxide bonds, which is also the central step of metal catalysed carboxylation reactions. It was found that CO2 insertion into the cobalt(III)-alkoxide bond of [(2-hydroxyethoxy)Co(III)(salen)(L)] complexes (salen = N,N"-bis(salicyliden-1,6-diaminophenyl)) is exothermic, whereby the exothermicity depends on the trans-ligand L. The more electron-donating this ligand is, the more exothermic the insertion step is. Interestingly, we found that the activation barrier decreases with increasing exothermicity of the CO2 insertion. Hereby, a linear Brønsted-Evans-Polanyi relationship was found between the activation energy and the reaction energy.
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Affiliation(s)
- Willem K Offermans
- CAT Catalytic Center, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Claudia Bizzarri
- CAT Catalytic Center, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Walter Leitner
- Lehrstuhl für Technische Chemie und Petrolchemie, ITMC, RWTH Aachen University, Worringerweg 1, D-52074 Aachen, Germany
| | - Thomas E Müller
- CAT Catalytic Center, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany
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A novel magnetic hybrid nanomaterial as a highly efficient and selective catalyst for alcohol oxidation based on new Schiff base complexes of transition metal ions. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcata.2014.10.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Fleck M, Layek M, Saha R, Bandyopadhyay D. Synthetic aspects, crystal structures and antibacterial activities of manganese(III) and cobalt(III) complexes containing a tetradentate Schiff base. TRANSIT METAL CHEM 2013. [DOI: 10.1007/s11243-013-9741-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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12
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Luo XJ, Zhang CH, Zhou J, Liu YC. Bis[4-chloro-2-(quinolin-8-yl-imino-meth-yl)phenolato-κ(3) N,N',O]cobalt(III) trichlorido-methano-lcobaltate(II). Acta Crystallogr Sect E Struct Rep Online 2013; 69:m278-9. [PMID: 23723781 PMCID: PMC3647815 DOI: 10.1107/s1600536813010118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 04/13/2013] [Indexed: 11/13/2022]
Abstract
The reaction of 4-chloro-2-(quinolin-8-yliminomethyl)phenol (HClQP) with cobalt(II) dichloride hexahydrate in methanol/chloroform under solvothermal conditions yielded the title compound, [Co(C16H10ClN2O)2][CoCl3(CH3OH)]. The CoIII atom is six-coordinated in a slightly distorted octahedral geometry by four N atoms and two O atoms of two tridentate HClQP ligands, which are nearly perpendicular to each other, making a dihedral angle of 86.95°. The CoII atom is four-coordinated by three Cl atoms and one O atom from a methanol ligand in a distorted tetrahedral geometry. The crystal packing is consolidated by intermolecular O—H⋯Cl, C—H⋯Cl and C—H⋯O hydrogen bonds, forming a three-dimensional supramolecular structure, in which [CoIICl3(CH3OH)] anions are connected via O—H⋯Cl and C—H⋯Cl hydrogen bonds into centrosymmetric dimers. Neighboring cobalt(III) complexes form dimers through C—H⋯O hydrogen bonds, as well as π–π stacking [centroid–centroid distances = 3.30 (2) Å] between the planar quinoline systems of one HClQP ligand and the phenolate ring of another.
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Affiliation(s)
- Xu-Jian Luo
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, People's Republic of China
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13
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Niu Y, Li H. Alternating copolymerization of carbon dioxide and cyclohexene oxide catalyzed by salen Co III(acetate) complexes. Colloid Polym Sci 2013; 291:2181-2189. [PMID: 23956484 PMCID: PMC3742425 DOI: 10.1007/s00396-013-2957-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/06/2013] [Accepted: 04/11/2013] [Indexed: 12/01/2022]
Abstract
A series of CoIII carboxylate based upon N,N,O,O-tetradentate Schiff base ligand framework have been prepared. X-ray diffraction analysis confirms that these Schiff base CoIII carboxylate are all monomeric species with a six-coordinated central Co in their solid structures. The activities and polycarbonate selectivity of these complexes toward the copolymerization of epoxide (cyclohexene oxide and propylene oxide) and carbon dioxide have been investigated in the presence of bis(triphenylphosphine)iminium chloride. Copolymerization experiments indicate that [bis(α-methyl-3,5-di-tertbutyl-salicylaldehyde) ethylenediiminato] CoIIIOOCH3 exhibits the highest activity and polycarbonate selectivity among these CoIII carboxylate. The resultant copolymer contained almost 100 % carbonate linkages with the molecular weight up to 71.8 kg mol−1 as well as narrow polymer dispersity index (polymer dispersity index = 1.5). The substituents and the mode of the bridging part between the two nitrogen atoms both exert significant influences upon the progress of the copolymerizations, influencing both the polycarbonate selectivity and the rate of copolymerization.
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Affiliation(s)
- Yongsheng Niu
- College of Chemistry & Pharmacy, Qingdao Agricultural University, Qingdao, 266109 China
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14
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Jana S, Dalapati S, Guchhait N. Proton transfer assisted charge transfer phenomena in photochromic Schiff bases and effect of -NEt2 groups to the anil Schiff bases. J Phys Chem A 2012; 116:10948-58. [PMID: 23098054 DOI: 10.1021/jp3079698] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photochromic Schiff bases 5-diethylamino-2-[(4-diethylamino-benzylidene)-hydrazonomethyl]-phenol (DDBHP) and N,N'-bis(4-N,N-diethylaminosalisalidene) hydrazine (DEASH) with both the proton and charge transfer moieties have been synthesized, and their photophysical properties such as excited state intramolecular charge transfer (ICT) and proton transfer (ESIPT) processes have been reported on the basis of steady-state and time-resolved spectral measurement in various solvents. The ground-state six-membered intramolecular hydrogen bonding network at the proton transfer site accelerates the ESIPT process for these compounds. Both the compounds show large Stokes-shifted emission bands for proton transfer and charge transfer processes. The hydrogen bonding solvents play a crucial role in these photophysical processes. Excited-state dipole moment of DDBHP and DEASH calculated by the solvatochromic method supports the polar character of the charge transfer excited state. Introduction of -NEt(2) groups to the reported salicylaldehyde azine (SAA) Schiff base results an increase in fluorescence lifetime from femtosecond to picosecond time scale for the proton transfer process.
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Affiliation(s)
- Sankar Jana
- Department of Chemistry, University of Calcutta, Kolkata-700009, India
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15
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Fleck M, Karmakar D, Ghosh M, Ghosh A, Saha R, Bandyopadhyay D. Synthetic aspects, crystal structure and antibacterial activity of two new Schiff base cobalt(III) complexes. Polyhedron 2012. [DOI: 10.1016/j.poly.2011.12.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Alternating copolymerization of CO2 with propylene oxide and terpolymerization with aliphatic epoxides by bifunctional cobalt Salen complex. Polym J 2010. [DOI: 10.1038/pj.2010.112] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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