0000000001299698
AUTHOR
Suman K. Barman
[CuII{(LISQ)˙−}2] (H2L: thioether-appended o-aminophenol ligand) monocation triggers change in donor site from N2O2 to N2O(2)S and valence-tautomerism
Using a potentially tridentate o-aminophenol-based redox-active ligand H2L1 (2-[2-(benzylthio)phenylamino]-4,6-di-tert-butylphenol) in its deprotonated form, [Cu(L1)2] has been synthesized and crystallized as [CuII(L1)2]·CH2Cl2 (1·CH2Cl2). A cyclic voltammetry experiment (in CH2Cl2; V vs. SCE (saturated calomel electrode)) on 1·CH2Cl2 exhibits two oxidative (E = 0.20 V (peak-to-peak separation, ΔEp = 100 mV) and E = 0.90 V (ΔEp = 140 mV)) and two reductive (E = -0.52 V (ΔEp = 110 mV) and E = -0.92 V (ΔEp = 120 mV)) responses. Upon oxidation using a stoichiometric amount of [FeIII(η5-C5H5)2](PF6), 1·CH2Cl2 yielded [Cu(L1)2](PF6) (2). Structural analysis (100 K) reveals that 1·CH2Cl2 is a fou…
Single-Molecule-Magnet Fe Fe and Antiferromagnetic Fe Coordination Clusters
Supported by endogenous (part of the ligand, in-built) phenoxo bridges provided by the ligand 2,6-bis[{{(5-bromo-2-hydroxybenzyl)}{(2-(pyridylethyl)}amino}methyl]-4-methylphenol) (H3L), in its deprotonated form, exogenous (not part of the ligand, externally added or generated) oxo-/hydroxo- and acetato-bridged [FeII4FeIII2(O)2(O2CMe)4(L)2]·4Et2O (1) and [FeIII4(OH)2(O2CMe)3(L)2](ClO4)·3MeCN·2H2O (2) coordination clusters have been synthesized and structurally characterized. Complexes 1 and 2 have μ4-O and μ3-OH bridges, respectively. Magnetic studies on 1 reveal slow magnetic relaxation below 2 K. Both in-phase ( χ'M) and out-of-phase (χ″M) magnetic susceptibility were found to be frequency…
Six-coordinate [CoIII(L)2]z (z = 1−, 0, 1+) complexes of an azo-appended o-aminophenolate in amidate(2−) and iminosemiquinonate π-radical (1−) redox-levels: the existence of valence-tautomerism
Aerobic reaction of the ligand H2L1, 2-(2-phenylazo)-anilino-4,6-di-tert-butylphenol, CoCl2·6H2O and Et3N in MeOH under refluxing conditions produces, after work-up and recrystallization, black crystals of [Co(L1)2] (1). When examined by cyclic voltammetry, 1 displays in CH2Cl2 three one-electron redox responses: two oxidative, E11/2 = 0.30 V (peak-to-peak separation, ΔEp = 100 mV) and E21/2 = 1.04 V (ΔEp = 120 mV), and one reductive E1/2 = −0.27 V (ΔEp = 120 mV) vs. SCE. Consequently, 1 is chemically oxidized by 1 equiv. of [FeIII(η5-C5H5)2][PF6], affording the isolation of deep purple crystals of [Co(L1)2][PF6]·2CH2Cl2 (2), and one-electron reduction with [CoII(η5-C5H5)2] yielded bluish-b…
A phenoxo-bridged dicopper(ii) complex as a model for phosphatase activity: mechanistic insights from a combined experimental and computational study
A μ-phenoxo-bis(μ2-1,3-acetato)-bridged dicopper(II) complex [CuII2(L1)(μ-O2CMe)2][NO3] (1) has been synthesized from the perspective of modeling phosphodiesterase activity. Structural characterization was done initially with 1·3Et2O (vapour diffusion of Et2O into MeOH solution of 1; poor crystal quality) and finally with its perchlorate salt [CuII2(L1)(μ-O2CMe)2][ClO4]·1.375MeCN·0.25H2O, crystallized from vapour diffusion of n-pentane into a MeCN–MeOH mixture (comparatively better crystal quality). An asymmetric unit of such a crystal contains two independent molecules of compositions [CuII2(L1)(μ-O2CMe)2][ClO4] and [CuII2(L1)(μ-O2CMe)2(MeCN)][ClO4] (coordinated MeCN with 0.75 occupancy), …
Nickel(II) Complex of a Hexadentate Ligand with Two o-Iminosemiquinonato(1-) π-Radical Units and Its Monocation and Dication.
Aerobic reaction of a hexadentate redox-active o-aminophenol-based ligand, H4L(3) = N,N'-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2'-diamino(diphenyldithio)-ethane, in CH3OH with Ni(II)(O2CCH3)2·4H2O and Et3N afforded isolation of a reddish-brown crystalline solid [Ni(L(3))] 1. Cyclic voltammetry (CV) experiment exhibits two oxidative responses at E1/2 = 0.09 and 0.53 V vs SCE (saturated calomel electrode). Chemical oxidation of 1 in air by [Fe(III)(η(5)-C5H5)2][PF6] and AgBF4 in CH2Cl2 led to the isolation of one-electron oxidized species [1](1+) as purple [1][PF6]·CH2Cl2 and two-electron oxidized species [1](2+) as dark purple [1][BF4]2·CH2Cl2, respectively. X-ray crystallographic analysi…
Isostructural Dinuclear Phenoxo-/Acetato-Bridged Manganese(II), Cobalt(II), and Zinc(II) Complexes with Labile Sites: Kinetics of Transesterification of 2-Hydroxypropyl-p-nitrophenylphosphate
Using the dinucleating phenol-based ligand 2,6-bis[3-(pyridin-2-yl)pyrazol-1-ylmethyl]-4-methylphenol] (HL(2)), in its deprotonated form, the six new dinuclear complexes [M(II)(2)(L(2))(μ-O(2)CMe)(2)(MeCN)(2)][PF(6)] (M = Mn (2a), Co (3a), Zn (4a)) and [M(II)(2)(L(2))(μ-O(2)CMe)(2)(MeCN)(2)][BPh(4)] (M = Mn (2b), Co (3b), Zn (4b)) have been synthesized. Crystallographic analyses on 2b·2MeCN, 3b·2MeCN, and 4b·2MeCN reveal that these complexes have closely similar μ-phenoxo bis(μ-carboxylato) structures. The physicochemical properties (absorption and ESI-MS spectral data, 2a,b, 3a,b, and 4a,b; (1)H NMR, 4a,b) of the cations of 2a-4a are identical with those of 2b-4b. Each metal ion is termina…
A Bioinspired Dinickel(II) Hydrolase: Solvent Vapor-Induced Hydrolysis of Carboxyesters under Ambient Conditions
From the perspective of synthetic metallohydrolases, a phenoxo-bridged dinickel(II) complex [NiII2(L)(H2O)2(CH3OH)][ClO4]·CH3OH (1) (H3L = 2,6-bis[{{(5-bromo-2-hydroxybenzyl)(N′,N″-(dimethylamino)ethyl)}amino}methyl]-4-methylphenol) has been synthesized and structurally characterized. The presence of a vacant coordination site and a weakly bound water molecule provides the scope for substrate binding to act as a metallohydrolase model. Ethyl acetate vapor diffusion at 298 K to a CH3CN/CH3OH solution of 1 results in the formation of a pentanuclear acetato-bridged complex [NiII5(H2L)2(μ3-OH)2(μ-O2CCH3)4][ClO4]2·CH3CO2C2H5 (2), demonstrating for the first time the metal-coordinated water-promo…
CCDC 1496680: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2016|Inorg.Chem.|55|12696|doi:10.1021/acs.inorgchem.6b01895
CCDC 1424158: Experimental Crystal Structure Determination
Related Article: Akram Ali, Debanjan Dhar, Suman K. Barman, Francesc Lloret, and Rabindranath Mukherjee|2016|Inorg.Chem.|55|5759|doi:10.1021/acs.inorgchem.5b02688
CCDC 1567091: Experimental Crystal Structure Determination
Related Article: Amit Rajput, Anuj Kumar Sharma, Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2018|Dalton Trans.|47|17086|doi:10.1039/C8DT03257B
CCDC 1866837: Experimental Crystal Structure Determination
Related Article: Amit Rajput, Anannya Saha, Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2019|Dalton Trans.|48|1795|doi:10.1039/C8DT03778G
CCDC 1424159: Experimental Crystal Structure Determination
Related Article: Akram Ali, Debanjan Dhar, Suman K. Barman, Francesc Lloret, and Rabindranath Mukherjee|2016|Inorg.Chem.|55|5759|doi:10.1021/acs.inorgchem.5b02688
CCDC 1424160: Experimental Crystal Structure Determination
Related Article: Akram Ali, Debanjan Dhar, Suman K. Barman, Francesc Lloret, and Rabindranath Mukherjee|2016|Inorg.Chem.|55|5759|doi:10.1021/acs.inorgchem.5b02688
CCDC 1866835: Experimental Crystal Structure Determination
Related Article: Amit Rajput, Anannya Saha, Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2019|Dalton Trans.|48|1795|doi:10.1039/C8DT03778G
CCDC 1866836: Experimental Crystal Structure Determination
Related Article: Amit Rajput, Anannya Saha, Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2019|Dalton Trans.|48|1795|doi:10.1039/C8DT03778G
CCDC 1496651: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2016|Inorg.Chem.|55|12696|doi:10.1021/acs.inorgchem.6b01895
CCDC 1849001: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Joan Cano, Francesc Lloret, Rabindranath Mukherjee|2019|Inorg.Chem.|58|8086|doi:10.1021/acs.inorgchem.9b00828
CCDC 1496758: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2016|Inorg.Chem.|55|12696|doi:10.1021/acs.inorgchem.6b01895
CCDC 1496674: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2016|Inorg.Chem.|55|12696|doi:10.1021/acs.inorgchem.6b01895
CCDC 1527528: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Totan Mondal, Debasis Koley, Francesc Lloret, Rabindranath Mukherjee|2017|Dalton Trans.|46|4038|doi:10.1039/C6DT03514K
CCDC 1496742: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2016|Inorg.Chem.|55|12696|doi:10.1021/acs.inorgchem.6b01895
CCDC 1567090: Experimental Crystal Structure Determination
Related Article: Amit Rajput, Anuj Kumar Sharma, Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2018|Dalton Trans.|47|17086|doi:10.1039/C8DT03257B
CCDC 1567092: Experimental Crystal Structure Determination
Related Article: Amit Rajput, Anuj Kumar Sharma, Suman K. Barman, Francesc Lloret, Rabindranath Mukherjee|2018|Dalton Trans.|47|17086|doi:10.1039/C8DT03257B
CCDC 1849015: Experimental Crystal Structure Determination
Related Article: Suman K. Barman, Joan Cano, Francesc Lloret, Rabindranath Mukherjee|2019|Inorg.Chem.|58|8086|doi:10.1021/acs.inorgchem.9b00828