Synthesis and Crystal Structures of γ-Type Octamolybdates Coordinated by Chiral Lysines

Abstract

The acidification of aqueous solutions containing Na2MoO4·2H2O in the presence of a chiral lysine ligand (d- and l-form) gives octamolybdates coordinating two lysine ligands, Na2[Mo8O26(d-lysH2)2]·8H2O (Mo8-d) and Na2[Mo8O26(l-lysH2)2]·8H2O (Mo8-l) (where lysH2 is 2,6-diammoniohexanoato), respectively. These two compounds crystallize with triclinic symmetry in the space group P1, the cell parameters being a = 10.782(2), b = 11.241(5), c = 10.027(2) Å, α = 93.21(2), β = 102.86(2), γ = 112.98(2)°, V = 1077(1) Å3, and Z = 1 for the Mo8-d, and a = 10.783(4), b = 11.246(3), c = 10.019(4) Å, α = 93.21(3), β = 102.75(3), γ = 112.98(2)°, V = 1077(2) Å3, and Z = 1 for Mo8-l. The X-ray crystal structures of these two species have been solved by the MITHRIL direct method and refined to R = 0.0337 and 0.0312 for Mo8-d and -l, respectively. The chiral lysine ligands are coordinated via their carboxylate-oxygen atoms at the vacant sites on the two five-coordinate molybdenum for the centrosymmetric γ-[Mo8O26]4− anion to retain their configuration with a resultant formation of optically-active octamolybdate species.

Crystal Structure of [Bis(L-Alaninato)Diaqua]Nickel(II) Dihydrate

“…Transition metal complexes with Schiff-base ligand containing the carboxylate group have been of great interest due to their importance as essentially biologically active [1][2][3] models for metalloproteins [4] and their various geometry aspects [5]. Metals bound to amino acids are essential for the catalytic function of certain enzymes, and their chemistry has received a great deal of research interest due to their significant interaction with enzymes and with different organic ligands which enables a better understanding of the antitumor/viral activities of this class of compounds and for modeling substrates involved in enzyme inhibition [6,7]. A number of complexes of amino acids with many transition metal ions have been prepared and thoroughly studied [8][9][10][11][12][13][14].…”

Heteropolymolybdates of AsIII, SbIII, BiIII, SeIV, and TeIV Functionalized by Amino Acids

“…For the present study, a thin alumina film grown on a metallic NiAl(110) substrate was used, [10] which enabled us to apply scanning tunneling microscopy (STM) as well as temperature-programmed desorption (TPD) for the charac-…”

The crystal structure of hexaammonium diacetyl-octa-molybdate tetrahydrate

“…Its colour changes gradually from colourless to brown upon exposure to the sunlight, and such a photo-physical feature has also been observed in the crystals of other related octamolybdates [1][2][3][4]. This compound crystallizes in triclinic system with space group symmetry of P1.…”