Saroj K. S. Hazari

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.

Vanadium(IV and V) Complexes Containing SNO (Dithiocarbonylhydrazone; Thiosemicarbazone) Donor Sets

The VO2+ complexes [VOCl(ONS)] (3) and [VO(ONS)′] (4), and the VO3+ complexes [VO(OEt)(ONS)′] (5) {ONS = (R)-salicylaldehyde thiosemicarbazonate(1−) R = 5,6-C4H4 (3a) or 3-OMe (3b); (ONS)′ = (R)-salicylaldehyde[benzylmercaptothiocarbonylhydrazonate(2−)], R = H, (4a/5a) or 3-OMe (4b/5b)} have been prepared and characterised by IR, EPR, 1H-, and 51V-NMR spectroscopy. In (S)-sBuOH, 4a converts to [VO{(S)-OsBu}(ONS)′] (5c) and [VO(OH)(ONS)′] (or a condensation product thereof). Solutions of 5c show three 51V NMR signals, two of which are due to two diastereomers. The EPR spectra of 3 and 4 in THF reveal the presence of octahedral species in solution. The crystal and molecular structures of complexes 3a·OCMe2, 5a, and 5b have been obtained, revealing basically a tetragonal pyramid, and coordination of the sulfur function in the thiocarbonyl (3) or enethiolate mode (5). The relevance of the compounds to bioinorganic aspects is addressed.

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.

cis-(Nitrato-κ(2)O,O')(2,5,5,7,9,12,12,14-octa-methyl-1,4,8,11-tetra-aza-cyclo-tetra-decane-κ(4)N,N',N'',N''')cadmium nitrate hemihydrate.

The CdII atom in the title complex, [Cd(NO3)(C18H40N4)]NO3·0.5H2O, is coordinated within a cis-N4O2 donor set provided by the tetradentate macrocyclic ligand and two O atoms of a nitrate anion; the coordination geometry is distorted octahedral. The lattice water molecule is located on a twofold rotation axis. N—H⋯O hydrogen bonds and weak C—H⋯O interactions link the complex cations into a supramolecular layer in the bc plane. Layers are connected by O—H⋯O hydrogen bonds between the lattice water molecule and the non-coordinating nitrate anion, as well as by weak C—H⋯O contacts.

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.

(Acetato-κO)(2,5,5,7,9,12,12,14-octa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4N,N′,N′′,N′′′)zinc perchlorate

The ZnII atom in the cation of the title salt, [Zn(C2H3O2)(C18H40N4)]ClO4, is five-coordinated by the four N atoms of the macrocycle and the O atom of the monodentate acetate ligand. The N4O donor set is based on a trigonal bipyramid with two N atoms occupying axial positions [N—Zn—N = 170.89 (16)°]. The perchlorate anions are associated with the cations via N—H⋯O hydrogen bonds; intramolecular N—H⋯O(acetate) interactions are also observed. The neutral aggregates are connected into an helical chain along the b axis via N—H⋯O(acetate) hydrogen bonds. The perchlorate anion was found to be disordered about a pseudo-threefold axis: the major component of the disorder had a site occupancy factor of 0.692 (11).