Inorganic salts of biguanide – Searching for new materials for second harmonic generation
作者:Irena Matulková、Ivan Němec、Ivana Císařová、Petr Němec、Zdeněk Mička
DOI:10.1016/j.molstruc.2007.11.015
日期:2008.8
Five inorganic salts of biguanide with carbonic, nitric, phosphoric and phosphorous acids were prepared and X-ray structural analysis has been performed for three novel compounds. Biguanidium(1+) phosphite trihydrate crystallizes in the triclinic space group P (1) over bar, 7.1470(1) angstrom, b = 9.6530(2) angstrom, c = 11.3140(2) angstrom, alpha = 70.094(1)degrees, beta = 75.688(1)degrees, gamma = 86.099(1)degrees, V = 713.71(2) angstrom(3), Z = 2, R = 0.0350 for 3031 observed reflections. The crystal structure is based on a network of phosphite anions and water molecules.Biguanidium(1+) cations form pairs through two intermolecular hydrogen bonds of the N-H center dot center dot center dot N type and fill the network with anions and water molecules.Biguanidium(2+) phosphite monohydrate crystallizes in the triclinic space group P (1) over bar, a = 6.9690(2) angstrom, b = 7.3500(3) angstrom, c = 8.1730(3) angstrom, alpha = 82.518(2)degrees, beta = 83.015(2)degrees, gamma = 82.811(2)degrees, V = 409.44(3) angstrom(3), Z = 2, R = 0.0308 for 1779 observed reflections. The structure is formed of a network of alternating biguanidium(2+) cations, phosphite anions and pairs of water molecules interconnected by a system of intermolecular hydrogen bonds. Biguanidium(2+) hydrogen phosphate monohydrate crystallizes in the triclinic space group P (1) over bar, a = 7.0630(2) angstrom, b = 7.8740(3) angstrom, c = 8.1120(3) angstrom, alpha = 102.706(2)degrees, beta = 104.976(2)degrees, gamma = 92.632(3)degrees, V = 422.61(3) angstrom(3), Z = 2, R = 0.0337 for 1827 observed reflections. The crystal structure is formed by pairs of anions that are mutually connected in chains through two water molecules. These chains are interconnected by biguanidium(2+) cations to form a three-dimensional network. TheFTIR and FT Raman spectra of all five compounds were recorded, calculated (HF, B3LYP and MP2 methods) and discussed.Quantitative measurements of second harmonic generation of powdered biguanidium(2+) nitrate and novel biguanidium(2+) carbonate monohydrate at 800 nm were performed and a relative efficiency (compared to KDP) of 87% and 20%, was observed, respectively. (C) 2007 Elsevier B.V. All rights reserved.