Band 34, Heft 1-2

No abstract available

The structure of C 2 O 4 (SnPh 3 ) 2 . 2dimethylformamide (DMF) has been determined by X-ray. It consists of monomers containing SnPh 3 residue trans coordinated by DMF, with the environment around the tin centre being trigonal bipyramidal.

The complex [Cd(L)Cl](Cl) 0.5 (Cl) 0.5· H 2 O (L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0 1.18 ,0 7.12 ]docosane has been synthesized and structurally characterized by X-ray diffraction. The compound crystallizes in the triclinic system P -1 with a =9.922(2), b =10.746(2), c =12.594(3) Å, α=112.40(3), β=99.54(3), γ=94.13(3)°, V =1210.7(4) Å 3 , Z =2. The coordination of the cadmium atom is a distorted square-pyramid with four secondary amines of the macrocycle occupying the basal sites and a terminal chlorine atom at the axial position.

C,N-chelated triorganotin(IV) compounds containing the L CN ligand, where L CN is {2-[(CH 3 ) 2 NCH 2 ]C 6 H 4 } -, reveal the monomeric structure in solution as well as in the solid state with pentacoordinated tin atom in trigonal bipyramidal coordination polyhedra. These compounds were used as mild and very efficient metathetical fluorinating agents in fluorinations of various organic, inorganic substrates and organometallic species containing E-Cl (E = C, Si, P, S and metal) bond(s) (metal halides, phosphines, silanes, etc.) as well as the F ion selective carriers with low detection limits.

No abstract available

Redox switched anthraquinone derived podands 1-(anthra­quinonyloxy), 3 methoxy methane (T 1 ) and 1,5 bis-(2-(2-hydroxyethoxy)ethoxy)anthracene-9-10-dione (T 2 ) have been synthesized by condensation of 1-chloroanthraquinone, 1,5-dichloro-anthraquinone with methoxy methanol and diethylene glycol in THF under N 2 atmosphere characterized by m.p., TLC and IR, NMR, Mass analysis. Extraction and transport of metal ions in oxidized and reduced state is Ca 2+ >K + >Li + , Li + >K + >Ca 2+ . The results of the transport study reveal that ionophore T 1 and T 2 are selective for Ca 2+ ; this selectivity can be used for fabrication of ion selective electrodes and sensors. Double-armed ionophore T 2 is a good extractant and is transporter for metal ions compared to single-armed podands. Extraction and transport ability enhanced in reduced state.

Microwave-assisted synthesis and spectroscopic studies of trimethyl and triphenyl germanium(IV) chelates derived from the reactions of organogermanium chlorides with the sodium salt of a biologically active nitrogen donor ligand are described. The resulting products have been isolated and characterized by elemental analyses, molecular weight determinations and conductance measurements, Systronics-Vadodara, India. On the basis of electronic, infrared, 1 H and 13 C NMR spectral studies, trigonal bipyramidal geometry has been suggested for the resulting complexes. The biologically active ligand and its corresponding complexes have been examined with regard to antifungal and antibacterial activity against pathogenic fungi and bacteria, and the results are rather encouraging. Both the compounds have also been found to act as nematicides by reducing the number of nematodes ( Meloidogyne incognita ).

The macrocyclic ligand 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L) reacts with cadmium(II) chloride and excess NaClO 4 to give a chloro-bridged dinuclear cadmium(II) complex [Cd(L)(μ-Cl)] 2 ·2ClO 4 ( 1 ). Each cadmium(II) ion exhibits a distorted octahedral environment with two chloride ligands and four secondary amines of the macrocycle. The compound 1 crystallizes in the orthorhombic system P bca with a =14.477(1), b =15.256(2), c =20.500(6) Å, V =4527.6(15) Å 3 , Z =4. Cyclic voltammetry of 1 gives one oxidation and two reduced processes.

The dinuclear cadmium(II) complex [Cd II (L)(μ-Cl)Cd II Cl 3 ] ( 1 ) (L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0 1.18 ,0 7.12 ]docosane) has been synthesized and structurally characterized by X-ray diffraction. The compound 1 crystallizes in the monoclinic system P 2 1 /n with a =8.45380(10), b =18.2348(3), c =17.4271(3) Å, β=100.957(1)°, V =2637.47(7) Å 3 , Z =4. The crystal structure of 1 reveals a chlorido-bridged dinuclear complex, in which the coordination environment around each cadmium atom exhibits a distorted square-pyramid and a distorted tetrahedron, respectively. Cyclic voltammetry of 1 gives one oxidation and two reduction processes.

The synthesis and complexive abilities of 5-mono­[(tert-butoxycarbonyl)-amino]-11,17,23-triamino-25,26,27,28-tetrabutoxycalix[4]arene (L1) and 5,11,17,23-tetrakis[(tert-butoxycarbonyl)-amino]-25,26,27,28-tetrabutoxycalix[4]arene (L2) towards the alkali cations Li + , Na + , K + , Rb + , Cs + and the alkali earth cations Mg +2 , Ca +2 , Sr +2 and Ba +2 in methanol-chloroform mixture have been evaluated at 25°C using UV-Vis spectrophotometric techniques. The results show that the ligands are capable of complexing with all the cations by 1:1 metal to ligand ratios. Molecular mechanics calculations have been used to model the geometries of the alkali and alkali earth cations with the ligands using the Hyperchem 7 computational package. The selectivity is presented considering that the calculated formation constants are in the order Li + >>Na + >K + >Rb + >Cs + and Mg +2 >Ca +2 >Sr +2 >Ba +2 with the ligands. Also, L1 shows more attraction towards the smaller alkali and alkali earth metal ions than L2.