Synthesis and reaction chemistry of monomeric and dimeric amide complexes of platinum(II)

Article abstract of DOI:10.1021/om00049a020

A series of complexes trans-[PtH(NH₃)L₂]ClO₄ (L = PPh₃, PEt₃, PCy₃), trans-[PtMe(NH₃)L₂]ClO₄ (L = PPh₃, PEt₃, PMePh₂, PCy₃), and [PtMe(NH₃)dppe]ClO₄ have been synthesized from trans-PtH(ClO₄)L₂, trans-PtMe(ClO₄)L₂, and PtMe(ClO₄)dppe and ammonia, respectively. Reacting trans-[PtH(NH₃)L₂]ClO₄ (L = PPh₃, PEt₃) with NaNH₂ gives [PtH(μ-NH₂)L]₂ as a mixture of anti and syn isomers. The complexes reductively eliminate ammonia. Reacting trans-[PtMe(NH₃)L₂]ClO₄ (L = PPh₃, PEt₃, PMePh₂) with NaNH₂ gives the stable complexes [PtMe(μ-NH₂)L]₂ as mixtures of anti and syn isomers. For L = PPh₃, PMePh₂, PEt₃, the percentage anti isomer is 100, 75, and 50, respectively. For L = PEt₃, the intermediate complex trans-PtMe(NH₂)(PEt₃)₂ has been observed. Reacting [PtMe(μ-NH₂)L]₂ with L (L = PPh₃, PEt₃) gives cis-PtMe(NH₂)L₂. Reacting trans-[PtH(NH₃)(PCy₃)₂]ClO₄, trans-[PtMe(NH₃)(PCy₃)₂]ClO₄, or trans-[PtPh(NH₃)(PCy₃)₂]ClO₄ with NaNH₂ gives trans-PtH(NH₂)(PCy₃)₂, trans-PtMe(NH₂)(PCy₃)₂, or trans-PtPh(NH₂)(PCy₃)₂. Reacting [PtMe(μ-Cl)PCy₃]₂ with AgClO₄ then NH₃ gives [PtMe(NH₃)₂PCy₃]ClO₄. Treating [PtMe(NH₃)₂PCy₃] with NaNH₂ gives an equimolar mixture of anti and syn isomers of [PtMe(μ-NH₂)PCy₃]₂. The syn isomer, which has been isolated, converts to a mixture of syn and anti in the presence of tricyclohexylphosphine in CDCl₃ solution. The compound anti-[PtMe(μ-NH₂)PPh₃]₂ crystallizes in the space group C2/c with a = 22.592 (5) A?, b = 11.844 (3) A?, c = 29.403 (6) A?, β = 116.43 (2)°, and Z = 8. The two crystallographically independent molecules with Pt(1)-Pt(1A) and Pt(2)-Pt(2A) distances of 3.106 (1) and 3.117 (1) A?, respectively, are associated by Pt?H interactions. The complex trans-PtMe(NH₂)(PCy₃)₂ reacts with CF₃SO₃H to give trans-[PtMe(NH₃)(PCy₃)₂]CF₃SO ₃. The complex trans-PtPh(NH₂)(PCy₃)₂ reacts with CF₃SO₃H and H₂O to give trans-[PtPh(NH₃)(PCy₃)₂]CF₃SO ₃ and trans-[PtPh(NH₃)(PCy₃)₂]OH, respectively. trans-PtPh(NH₂)(PCy₃)₂ reacts with methyl iodide and allyl chloride to give trans-PtPhI(PCy₃)₂ and trans-PtPhCl(PCy₃)₂, respectively. Carbon dioxide reacts with trans-PtPh(NH₂)(PCy₃)₂ to give trans-PtPh(NHCO₂H)(PCy₃)₂ then trans-PtPh(OCONH₂)(PCy₃)₂.