15558-15-3Relevant academic research and scientific papers
Heterobimetallic complexes containing Cu and Si
Siddiqi,Afaq, Hina,Nami, Shahab A. A.,Umar, Ahmad
, p. 1459 - 1468 (2003)
[Bis(propanediamine)Cu]Cl2, (1) was allowed to react with SiCl4 to yield a bimetallic complex (2). Compound (2) was then treated with pyridine to attain the maximum coordination number of silicon (3). The reaction was also followed conductometrically. Complex (3) was reacted with sodium diethyl dithiocarbamate (dtc) to yield (4). The dtc in (4) acts as a bidentate chelating agent as its IR spectrum showed the CS2 stretching frequency at 1020 cm-1 which is characteristic of a symmetrically bonded dithiocarbamate group. There is a common peak in the range 246 to 260 nm in the UV-Vis. spectra of (1), (2) and (3) due to L → M charge transfer. The EPR spectra of all species showed different environments for the Cu(II) ion in the various compounds indicating stereochemical changes.
Conformational flexibility of the di(1,3-diaminopropane)-copper(II) cation: Part 2 1. Structure determination for aqua-di(1,3-diaminopropane-N,N′)-copper(II) dichloride and chlorodi(1,3-diaminopropane-N,N′)-copper(II) chloride methanol solvate and DFT calculations for aqua-di(1,3-diaminopropane-N,N′)copper(II) cation
Sundberg, Markku R.,Sillanpaeae, Reijo,Uggla, Rolf
, p. 35 - 42 (2008/10/08)
The structures of aqua-di(1,3-diaminopropane-N,N′)copper(II) dichloride (1) and chloro-di(1,3-diaminopropane-N,N′)copper(II) chloride methanol solvate (2) were determined by single crystal X-ray methods. [Cu(tn)2H2O]Cl2 (1) (tn = 1,3-diaminopropane), C6H22Cl2CuN4O,Mr = 300.72, tetragonal, space group P42nm (No. 102), a = 9.3146(5), c = 7.591(1) A, V = 658.63(9) A3,Z = 2,Dc = 1.516 g cm-3. [Cu(tn)2Cl]Cl·MeOH (2), C7H24Cl2CuN4O,Mr = 314.74, monoclinic, space group P21/c (No. 14), a = 8.598(2), b = 16.176(2), c = 10.418(4) A, β = 107.11(3)°, V = 1384.7(7) A3, Z = 4, Dc = 1.510 g cm-3. Compound 1 is formed in aqueous solution, whereas 2 was obtained in methanol. The coordination polyhedron in 1 is square pyramid with exceptionally high site symmetry of 4mm (C4v) around the copper(II) cation. The distances from the central copper(II) cation to the two nearest chloride ions are different in 2, 2.736(2) and 3.322(2) A. If the remote chloride is not taken into consideration, the coordination polyhedron could be described as distorted square pyramid. In both compounds the chelate rings display chair conformation. In 1 the two tn ligands are coordinated to copper in syn-like fashion, whereas in 2 the rings are in normal anti-like conformation. The rare syn-like conformation is a stable conformation, since the overall geometry was not changed during optimization carried out at the LDA/DNP level of theory. The optimized syn-like conformation is favoured by 16.38 kJ mol-1 over the optimized anti-like conformation of the [Cu(tn)2(H2O)]2+ cation.
