Homo-valent diruthenium(II,II) carbonates Na 4 [Ru 2 (CO 3 ) 4 ]·10H 2 O: synthesis, structure, properties, and calculation.

Homo-valent diruthenium(II,II) carbonates have been underexplored hitherto. This paper reports the synthesis and crystal structure of a diruthenium(II,II) compound, Na 4 Ru 2 (CO 3 ) 4 ·10H 2 O (1). It has a two-dimensional structure in which the paddle-wheel diruthenium units of Ru 2 (CO 3 ) 4 4- are cross-linked through the carbonate groups. The investigation of the primary magnetic properties and theoretical studies with density functional theory (DFT) reveal that weak antiferromagnetic interactions are propagated between the Ru 2 units which contain two unpaired electrons in an electron configuration σ 2 π 4 δ 2 π* 2 δ* 2 with a ground state S = 1. According to Raman spectrum measurements combined with theoretical calculations, the strong peak at 356 cm -1 in the small-wavenumber region was assigned to the stretching of the Ru-Ru double bonds.