The platinacyclobutane complexes PtCl2(CH2CR1R2CH2)(C5H5N)2 (R1 = H, R2 = CH2OH; R1 = H, R2 = CHMeOH; R1 = H, R2 = CMe2OH; R1 = Me, R2 = CH2OH) were synthesized from [PtCl2(C2H4)]2, the cyclopropane derivative, and pyridine. The lanthanide shift reagent Eu(fod)3 was used to simplify the 1H NMR spectra. An attempt has been made to study the conformation of the metallacyclobutane ring in solution on the basis of these NMR spectra. A single-crystal X-ray diffraction study of PtCl2(CH2-C(CH3)(CH2OH)CH2)(C5H6N)2 was carried out. The compound crystallizes in the orthorhombic space group D152h–Pbca with eight molecules in a cell of dimensions a = 19.596 (7) Å, b = 13.893 (5) Å, c = 13.108 (5) Å, and V = 3569 Å3 (t = -151 °C). The final conventional and weighted agreement indices on F02 are R = 0.056 and Rw = 0.086. The metallacyclobutane is puckered by 1.0° in the solid state and can be compared with a puckering of ~27° determined from solution studies on a series of related platinacycles. This difference may be of relevance to olefin metathesis reaction mechanisms.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry