99686-44-9Relevant academic research and scientific papers
Synthesis and structural systematics of ethane-1,2-dithiolato complexes
Rao, Ch. Pulla,Dorfman,Holm
, p. 428 - 439 (2008/10/08)
Reaction systems with a constant 2:1 Na2edt:M(II,III) mole ratio (edt = ethane-1,2-dithiolate) have been shown to yield the following complexes, isolated as quaternary ammonium salts: [Ti(edt)3]2- (1), [V2(edt)4]2- (2), [Cr(edt)2]2- (3), [Mn(edt)2]2- (4), [Mn2(edt)4]2- (5), [Fe2(edt)4]2- (6), [Co(edt)2]2- (7), [Co(edt)2]- (8), [Ni2(edt)3]2- (9), [Cu3(edt)3]3- (10), [Zn(edt)2]2- (11), and [Cd(edt)2]2- (12). The following compounds have been structurally characterized by single-crystal X-ray diffraction (space group; crystal parameters; Z; unique data (I > (2-3)[σ(I)]); R/Rw). (Et4N)2(1): Pna21; a = 21.151 (4) A?, b = 9.671 (1) A?, c = 15.046 (3) A?; 4; 1865; 3.4/3.4. (Et4N)2(3): C2/c; a = 13.023 (2) A?, b = 17.369 (3) A?; c = 12.825 (2) A?, β = 103.97 (1)°; 4; 1631; 4.5/6.0. (Me4N)3(7·8): Pbca; a = 26.366 (6) A?, b = 16.943 (4) A?, c = 15.722 (3) A?; 8; 1695; 5.4/5.3. Na-(Me3NCH2Ph)2(10)·MeOH: P21/n; a = 10.344 (4) A?, b = 9.839 (4) A?, c = 36.511 (11) A?, β = 96.72 (3)°; 4; 4525; 5.4/6.4. (Et4N)2(11): P21/a; a = 12.793 (2) A?, b = 16.321 (4) A?, c = 12.942 (2) A?, β = 94.52 (2)°; 4; 3523; 3.6/4.1. (Et4N)2(12): P21/a; a = 12.987 (4) A?, b = 16.465 (6) A?, c = 13.015 (3) A?, β = 95.28 (2)°; 4; 3370; 3.6/4.0. Crystals of (Me4N)3[Co2(edt)4] contain a 1:1 mixture of 7 and 8. These results, together with previously published information, lead to the recognition of seven structural types of homoleptic edt complexes, which closely approach or achieve the indicated symmetry: octahedral (C3)-1; planar (D2h)-3, 8; tetrahedral (D2d)-4, 7, 11, 12; nonoctahedral tetrabridged dimer (D2)-2; lateral doubly bridged dimer (Ci)-5, 6; doubly bridged folded planar (Ci)- 9; cyclic trimer (C3)-10. The complex unit in crystals containing 10 is [Na(MeOH)[Cu3(edt)3]]2-, displaying a nonplanar Cu3(μ-S)3 ring, trigonal Cu(I) coordination, and three Cu(edt) chelate rings projecting outward from the same face of the Cu3S3 ring. Na+ is situated on the C3 axis and is tetrahedrally coordinated by three S atoms and the O atom of methanol. Metal(II) complexes follow normal stereochemical preferences. Extended Hu?ckel MO calculations suggest that D2 dimers of M(III) dn ions will be unstable when 4 ≥ 4 and provide a rationale of the stability of Ci dimers with n = 4, 5. Complex 8 is an example of the rare planar spin-triplet Co(III) configuration; its existence emphasizes the strong in-plane antibonding character induced by edt. The most significant metric feature of this ligand is its large bite distance flexibility (～3.1-3.6 A?). Parametric correlations of bite distance and M-S bond distance with the ionic potential per ligand are offered. M(edt) chelate rings have conformations ranging from half-chair to envelope, with the majority of conformations intermediate of these but biased toward the half-chair. Complexes 1-12 constitute the most structurally diverse set of homoleptic complexes yet characterized.
