Synthesis, Photophysical Properties, and Theoretical Studies of Hydride−Alkynyl Platinum(II) Complexes. Molecular Structures of [trans-PtH(C⋮CC5H4N-2)(PPh3)2] and [Pt(η2-HC⋮CCPh2OH)(PPh3)2]

• Published in: Organometallics 2000-10, Vol.19 (21), p.4385-4397
• Main Authors: Ara, Irene, Berenguer, Jesús R, Eguizábal, Eduardo, Forniés, Juan, Gómez, Julio, Lalinde, Elena, Sáez-Rocher, José M
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om000143u

A series of mononuclear, [trans-PtH(C⋮CR)(PPh3)2] (R = C5H4N-2 (1), (6-C⋮CH)C5H3N-2 (2), C6H4NH2-4 (3), (4-C⋮CH)C6H4 (4), (CH2)5C⋮CH (5)), and binuclear, [trans,trans-(PPh3)2HPt{μ-σ:σ-(C⋮C)2R}PtH(PPh3)2] (R = C5H3N-2 (7), C6H4-1,4 (8)), hydride−alkynyl platinum complexes has been prepared in good to moderate yields from the reactions of [trans-PtHCl(PPh3)2] with an excess of the corresponding alkyne in the presence of an excess of NEt2H and from the reactions of [trans-PtHCl(PPh3)2] with 1 equiv of 2 or 4 in the presence of diethylamine. An analogous reaction with HC⋮CCPh2OH leads to a mixture of [trans-PtH(C⋮CCPh2OH)(PPh3)2] (6a) and [Pt(η2-HC⋮CCPh2OH)(PPh3)2] (6b). The binuclear diyne complex [{(PPh3)2Pt}2{μ-η2:η2-(C⋮CH)2C6H4-1,4}] (9), prepared in high yield from [Pt(η2-C2H4)(PPh3)2] and HC⋮CC6H4-1,4-C⋮CH (0.5 equiv), is also formed in the reaction leading to 8. Complexes 5, 7, and 8 have been used as precursors to form the mixed-valence Pt(II)−Pt(0) complexes 10−12. The spectroscopic characterization of the complexes and X-ray crystal structure determination of 1 and 6b are included. Their absorption and some selected emission spectra, examined on the basis of theoretical studies (EHMO), are also reported.