Group 4 metal complexes of Ph4P2N4S2R- anions: preparation, structure and reactions with electrophiles
The reaction of [Li(Ph4P2N4S2R)THF]2 (R = Me, 'Bu, Ph, CH2PPI12) with the metallocene dihalides MCp2Cl2 (M = Ti, Zr, Hf) in THF produces complexes of the type MCp2Cl(Ph4P2N4S2R) in which the Ph4P2N4S2R" anion is bonded to the metal in an n* 12-N,S fashion as demonstrated by an X-ray structural determination of ZrCp2Cl-(Ph4P2N4S2‘Bu) (2a). Crystals of 2a are triclinic, space group Pi, with a = 12.439(4) Á, b =18.200(5) Á, c = 10.370(2) A, a = 100.40(2)°, ß = 106.65(2)°, y = 72.53(2)°, V= 2136(1) A3, and Z = 2. The final R and R„ values were 0.054 and 0.061, respectively. The dimensions of the three-membered ZrNS ring are d(Zr-S) = 2.634(2) A, </(Zr-N) = 2.206(5) A, and df(S-N) = 1.697(6) A. The treatment of 2a with electrophiles results in the regiospecific functionalization of the P2N4S2 ring. The reactions of 2a with methyl iodide or bromide produce the unsymmetrical S,S -diorgano derivative Ph4P2N4(S‘Bu)(SMe) and the S-bromo derivative Ph4P2N4(S‘Bu)- (SBr), respectively. By contrast, the reaction of 2a with 2 molar equiv of HC1 gas generates [Ph4P2N4S2‘BuH2]Cl (4) in which the two nitrogen atoms separated by the two-coordinate sulfur in the Ph4P2N4S2'Bu~ anion have been protonated. Compound 4 was characterized by 31P and *H-15N HMQC NMR spectra and by X-ray crystallography which revealed that 4 exists as a hydrogen-bonded dimer in the solid state. Crystals of 4 are triclinic, space group with a = 12.797(4) A, b = 14.618(3) A, c = 8.276(5) A, a = 90.48(3)°, ß = 105.59(3)°, y = 81.24(2)°, V = 1473(1) A3, and Z = 2. The final R and values were 0.045 and 0.033, respectively. An X-ray structural determination of Ph4P2N4(SPh)(SBr) (5b), prepared by bromination of [Li(Ph4P2N4S2Ph)THF]2 or [ZrCp2Cl-(Ph4P2N4S2Ph)], gave an S-Br distance of 2.573(5) A. Crystals of 5b are orthorhombic, space group P2I2121 with a =14.534(7) k,b =17.647(5) A, c =11.523(5) k,V= 2955(1) A3, and Z = 4. The final R and Rw values were 0.063 and 0.042, respectively. Surprisingly, the complex 2a does not react with strong nucleophiles such as Li-[EtsBH] or methyllithium.
Chivers, T., & Hilts, R. W. (1994). Group 4 metal complexes of Ph4P2N4S2R- anions: Preparation, structure and reaction.. Inorganic Chemistry, 33(16), 3459. https://doi.org/10.1021/ic00094a005
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