The diyne-bridged complexes Cp 2 Mo 2 (CO) 4 (μ-η 2 -C 1 4 H 2 0 ) (1) and [Cp 2 Mo 2 (CO) 4 ] 2 (μ,μ-η 2 ,η 2 -C 1 4 H 2 0 ) (2) have been prepared from the reactions of cyclotetradeca-1,8-diyne (C 1 4 H 2 0 ) with Cp 2 Mo 2 (CO) 6 in refluxing toluene, or with Cp 2 Mo 2 (CO) 4 at 25 o C. In contrast, Cp 2 Mo 2 (CO) 6 reacts with Ag + BF 4 - and C 1 4 H 2 0 to yield [CpMo + (CO)(μ,μ-η 2 ,η 2 -C 1 4 H 2 0 )] 2 (BF 4 - ) 2 (3-BF4) through redox cleavage of the Mo Mo bond. An alternative method to prepare 3-BF4 is via iodide abstraction of CpMoI(CO) 3 by Ag + BF 4 - in the presence of C 1 4 H 2 0 . Compound 3-BF4 reacts with Me 3 NO in acetonitrile to afford [CpMo + (NCMe)(μ,μ-η 2 ,η 2 -C 1 4 H 2 0 )] 2 (BF 4 - ) 2 (4-BF4). An alkyne alkyne coupling reaction is achieved by treating 3-BF4 with PPN + Cl - to yield the cyclobutadienophane complex CpMo(CO)Cl(η 4 -C 4 (C 1 0 H 2 0 )) (5). Metathesis of 3-BF4 with Na + BPh 4 - gives [CpMo + (CO)(μ,μ-η 2 ,η 2 -C 1 4 H 2 0 )] 2 (BPh 4 - ) 2 (3-BPh4), the crystal structure of which was determined by X-ray diffraction.