Synthesis and structural properties of the binary framework C-N compounds of Be, Mg, Al, and Tl

The synthesis of crystalline Be(CN)(2) and Mg(CN)(2) has been demonstrated and X-ray diffraction studies indicate simple-cubic structures with four-co ordinate metal atoms surrounded by an average of two N and two C atoms. The symmetry of Be(CN)(2) is Pn (3) over barm, a = 5.339(1) Angstrom, Z = 2, T he symmetry of Mg(CN)(2) is also Pn (3) over barm, a = 6.122(1) Angstrom, Z = 2, A thallium cyanide with composition TI(CN)2 was prepared and was shown to have a similar simple-cubic structure with a = 6.660(1) Angstrom, On th e basis of the X-ray diffraction pattern, IR spectra, and combustion analys is, this material is assigned the formula (TITIII)-T-I(CN)(4). Crystalline Al(CN)(3) with simple-cubic structure has been prepared for the first time. Rietveld refinement indicated that the structure incorporates CN groups wi th orientational disorder in a Prussian-blue-like Octahedral network. Al-27 NMR spectroscopy confirmed C,N disorder in cubic Al(CN)(3). The symmetry f or Al(CN)(3) is Pm (3) over barm, a=5.205(1)Angstrom. (C) 2001 Academic Pre ss.