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We have synthesized a bicopper(II) complex of N,N′,N″,N‴-tetra(2-aminoethyl)-1,1,2,2-ethanetetraamide and determined its crystal structure by X-ray diffraction. The complex has two dioxotetraamine sub-units linked by a CC bond. Each copper is situated in a square-pyramid consisting of four nitrogen atoms and one water molecule. The nitrogen atoms of the amido groups have stronger coordination ability than those of amino groups because of their deprotonation. The complex binds 10 water molecules and forms 22 hydrogen bonds. The large network of hydrogen bonds stabilizes the crystal. The complex has an EPR spectrum both in the solid and in frozen aqueous solution corresponding to mononuclear copper(II). Each copper has a magnetic moment of 1.74 μB. It has two redox processes at 0.62 and 0.79 V (vs SCE), respectively. IR, TG and conproportionation constants were also discussed.

Bonding mechanism of cis-Pt(NH_3)_2Cl_2 with DNA has been studied by CNDO/2 cal- culation.The computed results of the six models considered indicated that from the point of view of overlap population Q)(AB)and two atoms energy E_(AB),the most favorable bonding form was that between platinum and two N_7 atoms,from guanines(G)to form [(NH_3)_2PtG_2]~(2+).Thus,intrastrand cross-linkage mechanism which had been previously proposed by some authors was confirmed by our calculation.Chelation mechanism could not completely be excluded.Under certain conditions, it was possible for platinum to combine with a guanine through its N_7 and O(C_6)to form a chelate, but it was unstable as compared with [(NH_3)_2PtG_3]~(2+). Although the intrastrand cross-linkage mechanism is favored by our calculation,the question of how such a mode of combination hampers replication of DNA remains to be solved.

Sodium silicate in solution has been studed by ~(29)Si NMR spectroscopy. It was found that for solution of sodium silicate with mole number equal to 1, as the concentration of the solution lowered, the degree of polymerization decreased and the relative concentration of monosilicate anion increased, the lower the concen- tration of silicate solution, the more the relative concentration of monosilicate. It was also found that the regular changes of chemical shift δ and spin lattice relaxation time T_1 of various species of silicon and added salt effect on sodium silicate solution varied with mole number and concentration of the silicate in solution.

The solid state redox reaction of iron (III) oxalate with sodium nitrate and tin(II) chloride was investigated in hydrogen atmosphere and helium atmosphere by use of a non-isothermal technique. The evolved gases (EG) formed during the reaction were directly detected by gas chromatography, and the solid products were also identified by XRD, Mossbauer spectra and IR. The results show that the solid state redox reaction can go to completion because electron transfer is much easier than mass diffusion along the boundaries of the reactant. The releasing of crystal and coordination water during the redox reaction also facilitates completion of the reaction. The mechanism of the solid state reaction is also discussed.

Thermal decomposition of nitrourea salts (K, Na, Ag, Ba) was studied in hydrogen atmosphere, helium atmosphere and vacuum by gas chromatography and mass spectrometry. The evolution of dinitrogen oxide, water, hydrazine, nitrogen dioxide and the formation of cyanate salts during thermodecomposition of nitrourea salts in helium and hydrogen were confirmed. In vacuum the evolved gaseous products changed to dinitrogen oxide, water, nitrogen monoxide, nitrogen gas indicating that interreaction between evolved gaseous products occurred. The same solid products – cyanate salts – are formed showing vacuum having no effects upon the decomposition mechanism.