Synthesis and structure of methylpalladium(II) and -platinum(II) complexes with 2-allylphenoxido ligands, trans-PdMe(O6H4CH2CHCH2-o)(PR3)2 (R=Me, Ph) and PtMe(η1-O, η2-C,C-OC6H4CH2CHCH2-o)(PMe3). Simple O-coordination and chelating coordination depending on the metal center and auxiliary phosphine ligand
摘要:
Reactions of cis-PdMe2L2 (L = PMe3, PPh3, 0.5 dppp [dppp = Ph2P(CH2)(3)PPh2]) with equimolar 2-allylphenol afford the new complexes PdMe(OC6H4CH2CH=CH2-o)L2 (1: L = PMe3; 2: L = PPh3; 3: L = 0.5 dppp) in moderate to high yields. Addition of 2,2,2-trifluoro-1-phenylethanol to equimolar 1 results in formation of trans-PdMe(O6H4CH2CH=CH2-o)(PMe3)(2) . (HOCH(CF3) Ph), (4) which has been characterized by X-ray crystallography and NMR spectroscopy. Complex 4 contains O-H ... O hydrogen bonding between the allylphenoxido ligand and associated alcohol (O ... O = 2.635(6) Angstrom). The platinum complex PtMe(OC6H4CH2CH=CH2-o)(dppp), (5) is obtained from the alkoxido ligand exchange reaction of PtMe(OCH(CF3)(2))(dppp) with 2-allylphenol. Similar reaction of cis-PtMe(OR)(PMe3)(2) with equimolar 2-allylphenol at room temperature gives trans-PtMe(OC6H4CH2CH=CH2-o)(PMe3)(2) (6) in 55% yield. In contrast, reaction of cis-PtMe(OCH(CF3)(2))(PMe3)(2) . (HOCH(CF3)(2)) with excess 2-allylphenol at room temperature gives a mixture of 6 and PtMe(eta(1)-O, eta(2)-C, C-OC6H4CH2CH=CH2-o)(PMe3) (7) which are isolated in 16 and 28% yields, respectively. The isolated complex 7 has been characterized by NMR spectroscopy using several pulse techniques and X-ray analysis. The molecule has a distorted square-planar coordination around the metal center. The olefinic group in 2-allylphenoxido ligand is coordinated to the Pt center in a perpendicular fashion to the coordination plane. (C) 1998 Elsevier Science S.A. All rights reserved.