Co2Rh2(CO)12(1) reacts with alkynes (RC2R, R = C6F5 (2a), R = Ph (2b)) via specific insertion into the cobalt-cobalt bond to give Co2Rh2(CO)10(μ4-η2-RC2R) (3a,b). 3a was characterized by a single-crystal X-ray diffraction analysis: space group P21/c (No. 14), a = 11.286 (8) Å, b = 17.37 (1) Å, c = 16.65 (1) Å, β = 126.32 (5)°, V = 2630 (5) Å3, Z = 4, Dcalcd = 2.43 g/ cm3. A total of 2479 reflections (I ≥ 2σ) of 3215 reflections were used to give RF = 5.2% and RF2 = 5.6%. Reaction of 3a with CO and 2a results in regiospecific fragmentation to give CoRh(CO)6(μ-η2-F5C6C2C6F5) (4a) exclusively. 3b undergoes facile, reversible, and regiospecific fragmentation when treated with PhC2Ph (2b) and carbon monoxide to give CoRh(CO)6(μ-η2-PhC2Ph) (4b). Medium-pressure in situ IR studies have revealed that 3b reacts with carbon monoxide in a reversible and regiospecific reaction to give the 1:1 mixture of CoRh(CO)7(5) and 4b.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry