219802-70-7Relevant academic research and scientific papers
Coordination Chemistry of N-Alkylbenzamide-2,3-dithiolates as an Approach to Poly(dithiolate) Ligands: 1,4-Bis[(2,3-dimercaptobenzamido)methyl]benzene and Its Chelate Complex with the (C5H5)Ti Fragment
Seidel, Wolfram W.,Ekkehardt Hahn,Lügger, Thomas
, p. 6587 - 6596 (1998)
The bidentate dithiolate ligands N,N-diethyl-2,3-dimercaptobenzamide (H2-1), bis(N,N-diethyl-2,3-dimercaptoterephthalamide (H2-2), and 1,4-bis(hydroxymethyl)-2,3-dimercaptobenzene (H4-3) were synthesized from 2,3-dimercaptobenzoic acid or 2,3-dimercaptoterephthalic acid. The air-sensitive ligands form metallocene complexes of the type [η5-C5H5)2Ti(1)] (13), [η5-C5H5)2Mo(1)] (15), [(η5-C5H5)2Ti(3)] (16), and [(η5-C5H5)2Ti(2)] (17). Complexes 15 and 16 were characterized by X-ray diffraction. Selected crystallographic details for 15 are as follows: formula C21H23MoNOS2; M = 465.49; Pbca; a = 12.536(3), b = 14.313(3), c = 22.463(3) A?; V = 4031(2) A?3; Z = 8; R = 3.56 and Rw = 4.49 for 2111 structure factors (Fo2 ≥ 3σ(Fo2)) and 254 refined parameters. The molybdenum complex 15 shows an almost planar Mo(μ-S)2C2 chelate ring. Selected crystallographic details for 16 are as follows: formula C18H18O2S2Ti; M = 378.35; P1?; a = 10.1778(11), b = 11.5806(14), c = 22.967-(3) A?; α = 96.42(1), β = 101.74(1), α = 108.82(1)°; V = 2462.3(5) A?3; Z = 6; R = 4.79 and Rw = 13.27 for 5426 structure factors (I ≥ 2σ(I)) and 766 refined parameters. All titanocene derivatives assume the envelope conformation. The free activation energy for the flip around the S-S axis was determined for 13 to be 69 kJ/mol. The bis(dithiolate) ligand 1.4-bis[(2,3-dimercaptobenzamido)methyl]benzene (H4-4) was prepared from 2,3-dimercaptobenzoic acid and converted into the dinuclear air-stable titanocene complex [{(η5-C5H5)2Ti}2(4)] (19). Complex 19 reacts with HCl/CHCl3 with liberation of free H4-4 while reaction with NMe4Cl results in an intramolecular dithiolate shift under formal liberation of [(C5H5)3TiCl] and formation of the square-pyramidal chelate complex (NMe4)[(η5-C5H5)Ti(4)], (NMe4)[20]._ Crystallographic details for (NMe4)[20]·CH2Cl2 are as follows: formula C32H35Cl2N3O2S 4Ti: M = 740.67; P1?; a = 11.579(4), b = 12.210(4), c = 14.016(4) A?; α = 112.28(2), β = 94.46(3), γ = 104.22(3)?; V = 1744.9(10) A?3; Z = 2; R = 5.35 and Rw = 12.84 for 2870 structure factors (I ≥ 2σ(I)) and 397 refined parameters. The chelate rings in [20]- assume an endo/exo conformation.
