An unusual co-crystal [(mu(2)-dcpm)Ag-2(mu(2)-O2CH) (eta(2)-NO3)](2)center dot[(mu(2)-dcpm)(2)Ag-4(mu(2)-NO3)(4)] and its connection to the selective decarboxylation of formic acid in the gas phase

作者：Zavras Athanasios; White Jonathan M; O'Hair Richard A J^*

来源：Dalton Transactions, 2016, 45(48): 19408-19415.

DOI：10.1039/c6dt03700c

ESI/MS of an acetonitrile solution containing a mixture of AgNO3 : bis(dicyclohexylphosphino)methane (dcpm, L) : NaO2CH in a molar ratio of 2 : 1 : 1 gave an abundant peak due to [LAg2(O2CH)](+) and a minor peak assigned as [L2Ag4(O2CH)(3)](+). When this acetonitrile solution was frozen and layered with diethyl ether and left undisturbed for six days, crystalline material suitable for X-ray crystallography was identified and separated from amorphous solids. Single crystal X-ray diffraction revealed an unusual co-crystal consisting of two discrete tetranuclear silver clusters [(mu(2)-dcpm)Ag-2(mu(2)-O2CH)(eta(2)-NO3)](2)center dot[(mu(2)-dcpm)(2)Ag-4(mu(2)-NO3)(4)]. While all of the coordinated formates in [LAg2(O2CH)](+) and [L2Ag4(O2CH)(3)](+) can be decarboxylated in the gas-phase under conditions of collision induced dissociation, only the hydride [LAg2(H)](+) thus formed reacts with formic acid via protonation and liberation of H-2 to regenerate to formate, thereby closing a catalytic cycle for the selective decomposition of formic acid.

• 出版日期2016