Hydrothermal synthesis and characterization of (Me(4)N)[HgAsSe3], (Et(4)N)[HgAsSe3], and (Ph(4)P)(2)[Hg2As4Se11]: Novel 1-D mercury selenoarsenates

Three new mercury thioarsenates, (Me(4)N)[HgAsSe3], (Et(4)N) [HgAsSe3], and (Ph(4)P)(2)[Hg2As4Se11], With one-dimensional structures were synthesized hydrothermally from mixtures of HgCl2/3K(3)AsSe(3)/4(Me(4)NCl, Et(4)NBr, Ph(4)PBr), respectively, in sealed Pyrex tubes. The structures were determined by single-crystal X-ray diffraction analysis. (Me(4)N)[HgAsSe3] and (Et(4)N) [HgAsSe3] both crystallize in the monoclinic space group P2(1)/n (No. 14) with a = 7.115(1) Angstrom, b = 17.464(5) Angstrom, c = 9.356(2) Angstrom, beta = 91.34(1)degrees, Z = 4, V = 1162.2(7) Angstrom(3) for the former and a = 7.175(2) Angstrom, b = 18.907(4) Angstrom, c = 10.897(3) Angstrom, beta = 99.56(2)degrees, Z = 4, V = 1457(1) Angstrom(3) for the latter. They have the same one-dimensional chain-like anionic framework with trigonal planar Hg2+ and [AsSe3](3-) units. (Ph(4)P)(2)[Hg(2)AS(4)Se(11)] crystallizes in the triclinic space group P-l (No. 2) with a = 10.329(2) Angstrom, b = 17.017(3) Angstrom, c = 17.485(3) Angstrom, alpha = 92.70(1)degrees, beta = 105.73(1)degrees, gamma = 103.71(1)degrees, Z = 2, V = 2853(1) Angstrom(3). [Hg2As4, Se-11](2n-)(n), also possess a one-dimensional chain-like structure consisting of both trigonal-planar and tetrahedral Hg2+ ions. It contains a unique [As4Se11](6-) ligand which binds to four Hg2+ ions. The optical absorption and thermal properties of these compounds are reported. (C) 1996 Academic Press, Inc.