1401310-31-3Relevant academic research and scientific papers
Single-strand molecular wheels and coordination polymers in copper(II) benzoate chemistry by the employment of α-Benzoin oxime and azides: Synthesis, structures, and magnetic characterization
Stamatatos, Theocharis C.,Vlahopoulou, Gina,Raptopoulou, Catherine P.,Psycharis, Vassilis,Escuer, Albert,Christou, George,Perlepes, Spyros P.
, p. 3121 - 3131 (2012)
The use of α-benzoin oxime (bzoxH2) in copper(II) benzoate chemistry, in the absence or presence of ancillary azido ligands, is reported. The reaction of Cu(O2CPh)2A·2H2O with one equivalent of bzoxH2 in N,N-dimethylformamide (DMF) affords the decanuclear complex [Cu10(bzox)10(DMF)4] (1) in good yield. Dissolution of 1 in CH2Cl2 leads to the subsequent isolation of the solvent-free complex [Cu10(bzox) 10] (2) in moderate yields. Complexes 1 and 2 are isostructural and possess a loop or single-strand molecular wheel topology. The bzox2- dianions behave as I·1:I·1: I·2:μ3 ligands, which give rise to an overall [Cu10(μ-ONR)10(μ-OR')10] core. Both 1 and 2 stack to form nanotubular columns with beautiful supramolecular architectures. The reaction of Cu(O2CPh)2A· 2H2O with bzoxH2 and NaN3 in a 1:1:1 molar ratio in MeOH gives the bzoxH2-free complex [Cu(N3)(O 2CPh)(MeOH)]n (3), which is a 1D chain. The Cu II atoms in 3 are linked by a single, end-on N3 - group, a syn,syn-I·1: I·1:μ PhCO2- ion, and an oxygen atom from the bridging MeOH ligand. The 1D chains are hydrogen bonded into 2D sheets through NazideA·A·A· H(OMeOH) interactions. Variable-temperature, solid-state direct-current magnetic studies were carried out on 1-3. The data for 1 and 2 indicate very strong antiferromagnetic exchange interactions and a S = 0 ground state, which is expected for even-membered loop arrays of CuII atoms. In contrast, 3 exhibits ferromagnetic exchange interactions; the data were fitted to the appropriate equation derived from the Hamiltonian H = -JI￡(SiA·Si+1), which includes a zJ' interchain interaction term. The best-fit parameters were J = +49.6(4) cm-1, g = 2.067(3), and zJ' = 2.3(1) K. The combined results demonstrate the ligating flexibility of both the bzoxH2 and azido groups and their usefulness in the synthesis of polynuclear CuII clusters and coordination polymers.
