Synthesis, structure, and sunlight photolysis of benzyl- and tert-butyl-substituted octamethyltitanocene dihydrosulfides

0427878 - ÚFCH JH 2015 RIV CH eng J - Článek v odborném periodiku
Horáček, Michal - Císařová, I. - Gyepes, R. - Kubišta, Jiří - Pinkas, Jiří - Lamač, Martin - Mach, Karel
Synthesis, structure, and sunlight photolysis of benzyl- and tert-butyl-substituted octamethyltitanocene dihydrosulfides.
Journal of Organometallic Chemistry. Roč. 755, APR 2014 (2014), s. 141-150. ISSN 0022-328X. E-ISSN 1872-8561
Grant CEP: GA ČR(CZ) GAP207/12/2368; GA ČR GP203/09/P276
Institucionální podpora: RVO:61388955
Klíčová slova: titanium * titanocene * hydrosulphide
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 2.173, rok: 2014

New titanocene dihydrosulfide compounds [(C5Me4CH2Ph)(2)Ti(SH)(2)] (6) and [(C(5)Me(4)t-Bu)(2)Ti(SH)(2)] (7) were obtained by addition of hydrogen sulfide to the corresponding doubly tucked-in titanocenes, and titanocene hydrosulfide compounds [(C5Me4CH2Ph)(2)TiSH] (8) and [(C(5)Me(4)t-Bu)(2)TiSH] (9) by H2S-induced protonolysis of sigma-Ti-C bonds in [(eta(5)-C5Me4CH2Ph)Ti(III)(eta(5):eta(1)-C5Me4CH2-o-C6H4)] and [(C(5)Me(4)t-Bu)Ti(III)(eta(5):eta(1)-C5Me4CMe2CH2)], respectively. The crystal structures of 6, 8, and 9 and electronic absorption spectra of 6-9 in hexane solution highly resemble those of corresponding [Cp-2*Ti(SH)(2)] (1) and [Cp-2*TiSH] (2), however, compounds 6 and 7 strongly differ in their sensitivity to sunlight mutually and with respect to 1. The sunlight photolysis of 6 in toluene proceeded similarly to the process described previously for 1 except that about three times longer exposition (300 h) was required to obtain the cyclopentadienyltitanium sulfide cage cluster [{(C5Me4CH2Ph)Ti}(4)S-6] (10) in 48% yield. In contrast, compound 7 photo-decomposed very efficiently to give compound 9 as the only isolated titanium-containing product in 87% yield. The formation of 10 can be accounted for the redox elimination of the cyclopentadiene followed by elimination of hydrogen sulfide in intramolecular condensation reaction whereas the formation of 9 requires the dissociation of SH radicals. Both the processes were recognized by Rosenthal and Beweries to concur in photodecomposition of [Cp-2*Ti(OH)(2)].
Trvalý link: http://hdl.handle.net/11104/0233322