Synthesis and structure of methylpalladium(II) and -platinum(II) complexes with 2-allylphenoxido ligands, trans-PdMe(O6H4CH2CH=CH2-o)(PR3 )2 (R=Me, Ph) and PtMe(η1-O, η2-C,C-OC6H4CH2CH=CH2 -o)(PMe3).

Article abstract of DOI:10.1016/S0022-328X(97)00780-8

Reactions of cis-PdMe₂L₂ (L=PMe₃, PPh₃, 0.5 dppp [dppp=Ph₂P(CH₂)₃PPh₂]) 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)(PMe ₃)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) A). 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(η¹-O, η²-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.