Two helical one-dimensional complexes [MnII(MeOH)4][MnIV(L·)2]·2MeOH (1) and [MnIII(salen)][MnIII(L)2] (2) (H2L = HON=C(Ph)N=NC6H4CO2H) contain the noninnocent ligand [Mn(L·)2]2- and innocent low-spin [Mn(L)2]-. Intrachain anti-ferromagnetic interaction between adjacent manganese ions via the syn-anti carboxylate bridges in complex 1. Alternate syn-anti and anti-anti carboxylate bridges have been found to transmit ferro- and antiferromagnetic coupling between high-spin and low-spin Mn(III) ions in complex 2.
A novel copper-mediated solvothermal method was proposed for synthesizing colloidal spheres of a new composition,palladium iodide(PdI2).Typical procedure was designed to involve the introduction of cupric chloride(CuCl2) as weak oxidant.CuCl2 was found to be essential for preventing the easy formation of palladium deposits as well as facilitating the synthesis and assembly.Under the co-effect of CuCl2 and the surfactant of polyvinylpyrrolidone(PVP),neutral PdI2 colloidal spheres with narrow size distribution were successfully produced.Such ion-assisted synthetic method is believed to be prospective in producing well-constructed nanostructures.
CO oxidation has been performed on Co_(3)O_(4) nanobelts and nanocubes as model catalysts.The Co_(3)O_(4) nanobelts which have a predominance of exposed{011}planes are more active than Co_(3)O_(4) nanocubes with exposed{001}planes.Temperature programmed reduction of CO shows that Co_(3)O_(4) nanobelts have stronger reducing properties than Co_(3)O_(4) nanocubes.The essence of shape and crystal plane effect is revealed by the fact that turnover frequency of Co3+sites of{011}planes on Co_(3)O_(4) nanobelts is far higher than that of{001}planes on Co_(3)O_(4) nanocubes.
Ultrathin nanostructures have attracted much attention in recent years due to their predictable novel properties and various potential applications. The improvement in synthetic skills has led to many successful syntheses of nanostructures including zerodimensional (0D) nanoclusters, one-dimensional (1D) nanowires, two-dimensional (2D) nanosheets and other higher-level complex nanostructures, where cluster-assembly of primary nanocrystals is a common process. In this review, progress in ultrathin nanocrystals in the last decade and several important factors in the growth mechanisms are covered. By giving examples of cluster assembly from 1D to 3D nanostructures, the utility of cluster assembly in the synthesis of new materials has been demonstrated.
