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Some new diorganotin(IV) derivatives formulated as R 2 SnL (where R = Me, Bu, Ph and Oct) were obtained upon treatment of diorganotin(IV) precursors with acylhydrazones [H 2 L a  = N'-(2-hydroxy-3-methoxybenzylidene)furan-2-carbohydrazide, H 2 L b  = N'-(5-chloro-2-hydroxybenzylidene)furan-2-carbohydrazide and H 2 L c  = N'-(2-hydroxy-5-nitrobenzylidene)furan-2-carbohydrazide] derived from Schiff base condensation of furan-2-carbohydrazide and substituted salicylaldehydes in methanol in appropriate molar ratio. The enolic tridentate chelating mode of the acylhydrazones towards the diorganotin moieties [R 2 Sn(IV)] 2+ was ascertained by micro-analysis and various spectroscopic techniques viz., Fourier-transform infrared (FT-IR), multinuclear ( 1 H, 13 C and 119 Sn) magnetic resonance (NMR) and electrospray ionization mass (ESMS) spectrometry. The single crystal X-ray diffraction investigation of Me 2 SnL b and Ph 2 SnL b demonstrates that they crystallize in monoclinic space groups ‘P 2 1 ’ and ‘P 2 1 /c’ respectively, and comprised of crystallographically discrete 2 and 4 molecules in their respective unit cells. Both mononuclear complexes adopt a highly distorted square-pyramidal geometry (SP) wherein the imine nitrogen preferably occupies the apical site whereas the more electronegative enolic and phenolic oxygen atoms of the ligand and two carbon atoms of the methyl/phenyl groups of the organotin(IV) moiety align themselves equatorially around the five-coordinated tin center in a square plane. Diorganotin(IV) derivatives were also analyzed in air by thermo-gravimetric (TG, DTG and DTA) techniques to elucidate their thermal stability and decomposition trends. [ABSTRACT FROM AUTHOR]

Three novel binuclear diorganotin(IV) derivatives formulated as (R 2 Sn) 2 L (where R = Me, Bu and Ph) of a new symmetrical adipodihyrazone ligand, 1,6-bis(5-hydroxy-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)hexane-1,6-dione (H 4 L) derived from the Schiff base condensation of adipic acid dihydrazide and benzoylacetone in a 1:2 M ratio were synthesized. The micro-analysis and various spectroscopic techniques viz., infrared (IR), multinuclear ( 1 H, 13 C and 119 Sn) magnetic resonance (NMR) spectroscopy and electrospray ionization mass (ESMS) spectrometry were employed to establish the chelating mode of the dihyrazone ligand towards the diorganotin moieties [R 2 Sn(IV)] 2+ . The single crystal X-ray diffraction analysis of complex, (Me 2 Sn) 2 L reveals that it crystallizes in monoclinic space group ‘P 2 1 /n’ and consists of crystallographically discrete molecules. The complex has been investigated to prefer a highly distorted trigonal-bipyramidal geometry (TBP) over the square-pyramidal geometry (SP) around each tin centre wherein the more electronegative enolic and benzoylic oxygen atoms of the ligand are aligned axially, and two carbon atoms of the methyl groups attached to the tin metal atom and the imine nitrogen atom of the ligand aligned themselves equatorially around the tin centre in a trigonal plane. Thermal decomposition patterns of the dimethyl- and diphenyltin(IV) derivatives in air were also investigated by TG, DTG and DTA techniques. [ABSTRACT FROM AUTHOR]

New triphenyltin(IV) complexes of flexible tripodal Schiff base ligands, viz. tris(2-(2-hydroxybenzylidene)ethyl)amine) (H 3 saltren), tris(2-(2-hydroxyacetophenylidene)ethyl)amine) (H 3 hatren), and tris(2-(5-chloro-2-hydroxybenzylidene)ethyl)amine (H 3 5-Cl-saltren) have been synthesized. The coordination behaviour of Schiff bases towards triphenyltin(IV) moiety is discussed on the basis of electronic, infrared, multinuclear ( 1 H, 13 C, and 119 Sn) magnetic resonance (NMR) spectroscopic studies, and electrospray mass spectrometry (ESMS). Detailed single crystal X-ray studies demonstrate that adduct, Ph 3 SnCl.(H 3 trensal) crystallizes in orthorhombic space group, ‘P 2 1 2 1 2 1 ’ with cell parameters (a (Å) = 13.803(5), b (Å) = 21.117(5), c (Å) = 28.815(5)). The tin atom adopts a slightly distorted trigonal bipyramidal geometry wherein most electronegative chlorine and oxygen atoms are apically arranged, and ipso carbons of three phenyl rings of tin are aligned to constitute an equatorial plane around it. Thermal studies of all of the synthesized triphenyltin(IV) chloride adducts have also been carried out using TG, DTG and DTA techniques. [ABSTRACT FROM AUTHOR]

• Crystal structure of two new [Mn(Hmpth) 2 (bpy)] (1) and [Mn(Hmpth) 2 (o -phen)] (2) complexes • Spectroscopic and thermal studies of [Mn(Hmpth) 2 (bpy)] (1) and [Mn(Hmpth) 2 (o -phen)] (2) complexes • The photoluminescence activity of synthesized ligands and metal complexes. • Electrochemical characterizations of complexes through modified electrodes (MWCNT/Nf-Complexes). • Cyclic voltammetry studies indicate a reversible one electron transfer process corresponding to the Mn2+/3+ redox processes. Here, two complexes [Mn(Hmpth) 2 (bpy)] (1) and [Mn(Hmpth) 2 (o -phen)](2) with 1-(4-methoxybenzoyl)-4-phenyl-3-thiosemicarbazide (H 2 mpth) have been synthesized which contains 2-2′-bipyridine (bpy)/ o -phenanthroline (o -phen) as co-ligand. The ligand, H 2 mpth and its Mn(II) complexes have been characterized by IR, NMR, magnetic behaviour and single crystal X-ray data. In both complexes, the metal ions adopt a distorted octahedral geometry. Here, role of co-ligands (2,2-bpy and o -phen) on the optoelectronic properties of Mn(II) complexes is investigated for the first time. Complex 1 exhibits high fluorescence intensity as compared to ligand H 2 mpth and complex 2. The order of fluorescent behaviour found as complex 1 > complex 2 > H 2 mpth. Thermal behaviour of complexes were also studied. The electrochemical characteristics of Mn(II) complexes is studied using cyclic voltammetry technique after immobilizing it on the glassy carbon electrode modified with Nafion-multi-walled carbon nanotubes. The cyclic voltammetry studies indicate a reversible one electron transfer process corresponding to the Mn2+/3+ redox processes. [Display omitted] [ABSTRACT FROM AUTHOR]