The reaction of PhCH(OCH 3) 2 with Cp(CO) 3WH and HOTf gives [Cp(CO) 3W(PhCH 2OCH 3)] +OTf -. The structure of this benzyl methyl ether complex was determined by single crystal X-ray diffraction and was shown to have the ether bonded to tungsten through the oxygen. This compound was isolated as a kinetic product of the reaction; it decomposes in solution by releasing free PhCH 2OCH 3 and forming Cp(CO) 3WOTf. An analog with the BAr' 4 - counterion [Ar' = 3,5-bis(trifluoromethyl)phenyl] is more stable. The reaction of the vinyl acetal CH 2=CHCH(OEt) 2 with Cp(CO) 3WH and HOTf produces [Cp(CO) 3W(η 2-EtOCH=CHCH 3)] +OTf -, in which the ether is bonded to tungsten through the C=C bond of the vinyl ether. The crystal structure of this compound shows that the W-C(OEt) distance (2.69(3) Å) is significantly longer than the W-C(CH 3) distance (2.37(3) Å). There are weak C-H···O hydrogen bonds between both vinyl CH's and oxygens of triflate counterions. Evidence is presented that some of these weak hydrogen bonds are maintained in CD 2Cl 2 solution but not in CD 3CN.
ASJC Scopus subject areas