Benu K. Dey

Synthesis, Characterisation and Antifungal Activities of Some New Copper(II) Complexes of Isomeric 3,5,7,7,10,12,14,14-Octamethyl-1,4,8,11-Tetraazacyclotetradecanes

Three isomeric Me8[14]anes, LA, LB and LC, undergo complexation with copper(II) salts to form a series of [CuLXn(H2O)x]Xy.(H2O)z complexes where L = LA, LB and LC; X = Cl, Br, NO3; n, x, y and z may have values of 0, 1 or 2. The complexes have been characterised on the basis of analytical, spectroscopic, magnetic and conductance data. Further, the X-ray crystal structure of one complex, [CuLB(OH2)2](NO3)2, has been determined. The antifungal activity of all three isomeric ligands and their complexes has been investigated against a range of phytopathogenic fungi.

Axial ligand substitution in diastereoisomeric trans-[Co(Me8 14ane)Cl2]+ complexes and their anti-fungal activities

Three isomeric Me8 14anes, LA, LB and LC, on aeration with cobalt(II) acetate tetrahydrate and subsequent treatment with concentrated HCl and HClO4, give green trans-[CoLCl2]ClO4 diastereoisomers. Whereas the macrocyclic ligands LA and LB yield two N-chiral diastereoisomers, LC gives one isomer. The complexes undergo axial ligand substitution with small ligands such as , SCN−, OH− and H2O to produce corresponding trans products. Anti-fungal activities of the complexes against a range of phytopathogenic fungi have been investigated.

Synthesis, electrolytic behaviour and antimicrobial activities of cadmium complexes of isomers of 3,10-C- meso -3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane

Reactions of two diastereoisomers of 3,10-C-meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecanes, Me8[14]ane (LA and LB) with Cd(NO3)2 in methanol produced trans-[CdL(NO3)2] (L = LA or LB). However, the third diastereoisomer, Me8[14]ane (LC) did not react with Cd(NO3)2. Trans-[CdLB(NO3)2] undergoes axial ligand substitution reactions with KSCN, KNO2, KCl, KBr and KI, in the ratio of 1 : 2 to yield white solid products corresponding to molecular formula [CdLBX2] where X = NCS−, , Cl−, Br− or I−. Characterization has been carried out on the basis of elemental analysis, IR, UV-visible and 1H-, 13C- and 113Cd-NMR spectroscopy, as well as by magnetic moment and conductivity measurement. These complexes show different electrolytic behaviours in different solvents. In chloroform, they are noneletrolytic indicating that both anions coordinate to cadmium(II) with retention of original molecular formula [CdLBX2]; their 1 : 2 electrolytic nature in water reveals the formation of diaquo complexes [CdLB(H2O)2]X2. On the other hand, conductance values corresponding to 1 : 2 electrolyte in DMF indicate the formation of square pyramidal complexes [CdLB(DMF)]X2. The antimicrobial activities of these ligands and their complexes have been tested against some selected fungi and bacteria.

Synthesis, Characterisation and Anti-Fungal Activities of Some New Copper(II) Complexes of Octamethyl Tetraaza-Cyclotetradecadiene.

The ligand Me8[14]diene, L, in its free state as well as in the dihydroperchlorate form, L.2HClO4, coordinates copper(ll) in different salts to yield a series of [CuLXx] Xy(H2O)z complexes where X = NO3, ClO4, NCS, Cl and Br; x and y may have values of 0 or 2 and z = 0, 1 or 2. The complex, [CuL(ClO4)2].2H2O is found to undergo axial ligand substitution reactions with SCN-, NO3 and Cl- to give a variety of substitution derivatives: [CuL(ClO4)m Xn] where X = NCS, NO3 and Cl; m = 0 or 1, and n = 1 or 2. The complexes .have been characterised on the basis of analytical, spectroscopic, magnetic and conductance data. The anti-fungal activities of the ligand and its complexes have been investigated against a range of phytopathogenic fungi.

Characterization of Diastereoisomeric [Ni(Me8[14]ane)]2+ Cations

The isomeric Me8[l4]anes, designated by LA, LB and LC, on reaction with nickel(II) acetate tetrahydrate and subsequent addition of LiClO4·3HO yield yellow or orange-yellow square planar [NiL](ClO4)2 diastereoisomers. It has been possible to isolate two N-chiral diastereoisomers for each ligand and these give distinct infrared and 1H NMR spectra. The structures of these isomers have been assigned mainly on the basis of their 1H NMR spectra. One structure, namely [NiLBα ](ClO4)2, has been confirmed by x-ray crystallography.

Axial addition in diastereoisomeric [Cu(Me8 14ane)](ClO4)2 complexes: antifungal and antibacterial activities

A series of diastereoisomeric square planar copper(II) perchlorate complexes, [Cu(Me8[14]ane)](ClO4)2, undergo axial addition reactions with H2O, NCS− and to yield the octahedral species trans-[CuL1X2](ClO4) n (L1 = isomeric Me8[14]ane; X = H2O, NCS, NO2 or NO3; n = 2 when X = H2O; n = 0 when X = NCS, NO2 or NO3). The products have been characterized on the basis of analytical, spectroscopic, magnetic and conductance data. Some derivatives are unstable in open air and may react with adventious H2O to form diaquo complexes. Antifungal and antibacterial activities of the uncomplexed ligands, the square planar copper(II) complexes and their axial addition products have been investigated against a range of phytopathogenic fungi and bacteria.

Benzyl 2-methyl-3-[(E)-(thio­phen-2-yl)methyl­idene]dithio­carbazate

In the title compound, C14H14N2S3, the thione S atom and methyl group are syn, as are the two thioether S atoms. The molecule is twisted, the dihedral angles between the central (C2N2S2) residue and the pendent 2-thienyl and phenyl rings being 21.57 (6) and 77.54 (3)°, respectively. In the crystal, molecules assemble into a three-dimensional architecture via C—H⋯π interactions, involving both the five- and six-membered rings as acceptors, as well as S⋯S interactions [3.3406 (5) Å] between centrosymmetrically related 2-thienyl rings.

Synthesis, characterization, and antimicrobial studies of some palladium complexes with an octamethyl tetraazacyclotetradecadiene ligand and isomers of its reduced form

Biologically important tetraaza-macrocyclic ligand 3,10-C-meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene dihydroperchlorate, Me8[14]diene·2HClO4 (L1·2HClO4) was synthesized by the condensation of 1,2-diaminopropane with acetone in presence of quantitative amount of HClO4 and three isomeric ligands designated as LA, LB and LC were separated by the reduction of L1·2HClO4 with NaBH4 and fractional crystallization from xylene. The nitrato, nitro, bromido, and iodido complexes of palladium with diene ligand L1 were prepared by the interaction of L1·2HClO4 with K2[Pd(NO3)4], K2[Pd(NO2)4], K2[PdBr4], and K2[PdI4] (prepared by the reactions with PdCl2 with KNO3, KNO2, KBr, and KI, respectively), respectively. The bromide and iodido complexes of LA were prepared by the axial substitution reactions with [PdLACl2]Cl2. By contrast, similar complexes of other isomeric ligands LB and LC were prepared by axial addition reactions of [PdLʹ][PdCl4] (L′ = LB or LC) with KBr and KI, respectively. The complexes were characterized on the basis of elemental analysis: IR, 1H-NMR, UV–Vis spectroscopic analysis, and magnetic and molar conductivity data. The antifungal and antibacterial activities of these compounds have been studied against some phyto-pathogenic fungi and bacteria.

Studies on copper(II) complexes of N-pendant macrocyclic ligands

Saroj Kanti Singh Hazari1, Benu Dey2, Hazarat Miah3, Lucky Dey2, Suman Dasgupta2, Ratul Shil1, Shawon Barua2, Shah Alam2, Dieter Rehder4 1BGC Trust University Bangladesh, Chittagong, Bangladesh, 2Department of Chemistry, University of Chittagong, Chittagong, Bangladesh, 3Department of Pharmacy, BGC Trust University Bangladesh, Chittagong, Bangladesh, 4Department of Chemistry, University of Humburg, Humburg, Germany E-mail: sarojhazari@gmail.com

Bis(2,S-dimethyl­dithio­carbazate-κ2N3,S)(nitrato-κO)copper(II) nitrate

The title complex, [Cu(NO3)(C3H8N2S2)2]NO3, represents a low-symmetry polymorph (P-1, Z = 4) of a previously reported form [P-1, Z = 2; Ali et al. (2011 ▶). Polyhedron, 30, 542–548]. The CuII atom in each independent cation is found within a distorted square-pyramidal N2S2O coordination geometry defined by two N,S-bidentate ligands and an O atom derived from a monodentate nitrate. The primary difference between the cations is found in the relative orientations of the coordinated nitrate groups, which are directed to opposite sides of the molecule. Supramolecular layers along [110] and sustained by N—H⋯O interactions feature in the crystal packing. These are connected along the c axis by C—H⋯O interactions.