Synthesis and characterization of w=w doubly-bonded bimers [#eta#~5-rc_5h_4w(co)(#mu#-sph)]_2 and [#eta#~5-rc_5h_4w(#mu#-se)(#mu#-sph)]_2 (r=meo_2c, eto_2c). Crystal and molecrlar structure of trans/syn-[#eta#~5eto_2cc_5h_4w(#mu#-se)(#mu#-sph)]_2

摘要

The reaction of triply-bonded dimers [#eta#~5-rc_5h_4w]_2 with diphenyldisulfide affords doubly-bridged anddoubly-bonded dimers trans/anti-[#eta#~5-rc_5h_4w(co)(#mu#-sph)]_2 (1a,r =meo_2c; 2a, r =eto_2c) and trans/anti-[#eta#~5-rc_5h_4w(co)(#mu#-sph)]_2 (1b, r =meo_2c; 2b,r =eto_2c).Further reaction of a mixture of the trans/anti and trans/synisomers with elemental selenium leads to quadruply-bridged anddoubly-bonded dimers , trans/anti-[#eta#~5-rc_5h_4w(#mu#-se)(#mu#-sph)]_2 (3a,r =meo_2c; 4a, r =eto_2c) and trans/anti-[#eta#~5-rc_5h_4w(#mu#-se)(#mu#-sph)]_2 (3b, r =meo_2c;4b,r =eto_2c). All the above bridged w =w doubly-bonded dimershave been characterized by analysis, ir,~1h nmr and msspectroscopies, as well as for 4b by x-ray crystallography.