Synthesis and Structure of New Neutral Bimetallic Platinum Hydride Complexes
- Ara, I. 2
- Falvello, L.R. 2
- Forniés, J. 2
- Lalinde, E. 1
- Martín, A. 2
- Martínez, F. 2
- Moreno, M.T. 1
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1
Universidad de La Rioja
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2
Instituto de Nanociencia y Materiales de Aragón
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ISSN: 0276-7333
Año de publicación: 1997
Volumen: 16
Número: 25
Páginas: 5392-5405
Tipo: Artículo
Otras publicaciones en: Organometallics
Resumen
The reactions of mononuclear hydride complexes trans-[PtHXL2] with the solvated species Cis-[Pt(C6F5)2(thf)2] constitute a simple methodology to high-yield synthesis of dinuclear compounds with a mixed bridging system H/X. Thus, trans-[Pt(C≡CPh)H(PPh3)2] reacts readily with cis-[Pt(C6F5)2(thf)2] to give trans-[C6F5)(PPh 3Pt(μ-H)(μ-C≡CPh)Pt(C6F5)(PPh 3)] (1b), containing (X-ray) a μ-η1:η2-C≡CPh alkynyl ligand. trans-[Pt(C6F5)H(PPh3)2] reacts with cis-[Pt(C6F5)2(thf)2] under mild conditions to afford initially the 1:1 adduct trans,cis-[(C6F5)(PPh 3)Pt(μ-H)(μ(P)-η2-PPh3)Pt(C 6F5)2] (2a), which finally rearranges quantitatively to form cis-[(C6F5)(PPh3)Pt(μ-H)(μ-C 6F5)Pt(C6F5)(PPh3)] (2c). The crystal structures of 2a, a compound displaying an unusual PPh3 bridging ligand via the P donor atom and an η2-phenyl interaction, and 2c with a mixed pentafluorophenyl/hydride bridged system are reported. Similar hydride/chloride bridged diplatinum complexes [(C6F5)LPt(μ-H)(μ-Cl)Pt-(C6F 5)L] (3, L = PPh3; 4, L = PEt3), are also quantitatively formed by treatment of trans-[PtClHL2] with cis-[Pt(C6F5)2(thf)2] in CHCl3. Both complexes are obtained as trans isomers (3b and 4b), but their NMR data in CD3COCD3 indicate that they are present as a mixture of trans (3b, 4b) and cis (3c, 4c) isomers. Slow crystallization of 3b (CH2Cl2/hexane) in the presence of light gave crystals of the cis isomer 3c (X-ray), which is also quantitatively formed by photolysis of 3b. The presence of hydride bridging ligands in all complexes 1-4 is unambiguously confirmed by 1H NMR spectroscopy.