Complexes of dimolybdenum(II) with DL-amino acids. 2. Crystal structure of compounds containing DL-Valine and DL-Leucine

[Mo₂(D-Val)₂(L-Val)₂](ZnCl₄)₂·4H₂O(1) and [Mo₂(D-Leu)₂(LLeu)₂](PTS)₂Cl₂·2H₂O(2)(Val= Valine; Leu=Leucine; PTS=p-toluensulfonate) were prepared by reacting Mo₂⁴⁺ with the racemic amino acid in water followed by the addition of the appropriate counter ion. [Mo₂(D-Val)(LVal)(NCS)₄]·1 1 2 H₂O(3) was prepared by adding NCS^- ions to a solution of Mo₂⁴⁺ and DL-Valine. The structures of 1, 2 and 3 were determined by X-ray crystallography. Compound 1 is triclinic, space group P1 with a = 12.162(1), b=12.780(1), c=7.429(1) Å, α=106.52(2), β=92.61(3), γ=72.89(3)^o, V= 1057(I) ų and Z=1. Compound 02 is triclinic, space group P1 with a=9.326(I), b=15.546(2), c=9.092(1) Å, α= 92.41(3), β= 100.27(2), γ=76.87(2)^o, V= 1263(1) ų and Z=1. Compound 3 is triclinic, space group P1 with a=12.221(1), b=13.366(2), c=9.745(1) Å, α=104.39(2), β=103.50(3), γ=71.05(3)^o, V= 1438(1) ų and Z=2. In 1 and 2 the dimeric unit resides on a crystallographic center of symmetry and the four ligands are coordinated to the Mo₂⁴⁺ unit in the cyclic order of DDLL. In 3, the molecule has a cisoid arrangement of the amino acid ligands and the four NCS^- ligands.