Tuning the Nature and Formation of Bis(dihydrogen)-Osmium Species
Resumen: The influence of chelate ligands in the formation and nature of bis(dihydrogen) units of OsH4 complexes has been studied. The classical trihydride OsH3{¿2-C, N-(C6H4-py)}(PiPr3)2 (1) reacts with HBF4·OEt2 to give the Kubas-type dihydrogen-elongated dihydrogen derivative [Os{¿2-C, N-(C6H4-py)}(¿2-H2)2(PiPr3)2]BF4 (2), as a result of the protonation of one of the hydride ligands. Triflate (OTf) displaces the Kubas-type dihydrogen and elongates the elongated dihydrogen ligand, which is converted into a compressed dihydride. Thus, the addition of 1 equiv of HOTf to 1 leads to Os(H···H){¿2-C, N-(C6H4-py)}(OTf)(PiPr3)2 (3). Similar to [OTf]-, acetone reacts with 2 to afford the related compressed dihydride [Os(H···H){¿2-C, N-(C6H4-py)}(¿1-OCMe2)(PiPr3)2]BF4 (4), whereas acetonitrile leads to a 1:8 mixture of the monohydride [OsH(CH3CN)3(PiPr3)2]BF4 (5) and the trihydride [OsH3(CH3CN)2(PiPr3)2]BF4 (6). Reactions of 2 with toluene and p-xylene yield the half-sandwich derivatives [Os{¿2-C, N-(C6H4-py)}(¿6-toluene)(PiPr3)]BF4 (7) and [Os{¿2-C, N-(C6H4-py)}(¿6-p-xylene)(PiPr3)]BF4 (8), respectively. The acyl oxygen atom of the C, C-chelate ligand of the trihydride OsH3{¿2-C, C-[C(O)CH2ImMe]}(PiPr3)2 (10; Im = imidazolylidene) provides reliable and effective protection of the hydride ligands against the protonation. Thus, the addition of HBF4·OEt2 or HOTf to 10 leads to the trihydride-hydroxycarbene cation [OsH3{¿2-C, C-[C(OH)CH2ImMe]}(PiPr3)2]+ (11). The hydroxycarbene-NHC ligand of the latter is unstable, undergoing an intramolecular 1, 3-hydrogen shift, which produces the rupture of the chelate ligand and the formation of the cis-hydride dihydrogen (12a) and trans-hydride-dihydrogen (12b) derivatives [OsH(¿2-H2)(CO)(Me2Im)(PiPr3)2]+ (12). The protonation of 11 with a second equivalent of HOTf affords the transient bis(Kubas-type dihydrogen) [Os(¿2-H2)2{¿2-C, C-[C(OH)CH2ImMe]}(PiPr3)2](OTf)2, which undergoes the displacement of a coordinated hydrogen molecule by a [OTf]- anion to give the Kubas-type dihydrogen [Os(OTf)(¿2-H2){¿2-C, C-[C(OH)CH2ImMe]}(PiPr3)2]OTf (13). The addition of MeOTf to 10 leads to [OsH3{¿2-C, C-[C(OMe)CH2ImMe]}(PiPr3)2]OTf (14) which, in contrast to 11, is stable. Similar to the latter, the protonation of 14 with HOTf yields the Kubas-type dihydrogen complex [Os(OTf)(¿2-H2){¿2-C, C-[C(OMe)CH2ImMe]}(PiPr3)2]OTf (15).
Idioma: Inglés
DOI: 10.1021/acs.organomet.7b00787
Año: 2018
Publicado en: Organometallics 37, 3 (2018), 367-379
ISSN: 0276-7333

Factor impacto JCR: 4.1 (2018)
Categ. JCR: CHEMISTRY, ORGANIC rank: 11 / 57 = 0.193 (2018) - Q1 - T1
Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 5 / 45 = 0.111 (2018) - Q1 - T1

Factor impacto SCIMAGO: 1.473 - Inorganic Chemistry (Q1) - Physical and Theoretical Chemistry (Q1) - Organic Chemistry (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E35
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2016-81797-REDC
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2017-82935-P
Tipo y forma: Artículo (PostPrint)

Derechos Reservados Derechos reservados por el editor de la revista


Exportado de SIDERAL (2019-11-27-15:48:00)


Visitas y descargas

Este artículo se encuentra en las siguientes colecciones:
Artículos



 Registro creado el 2019-01-30, última modificación el 2019-11-27


Postprint:
 PDF
Valore este documento:

Rate this document:
1
2
3
 
(Sin ninguna reseña)