Axial-Site Modifications of Paddlewheel Diruthenium(II, II) Complexes Supported by Hydrogen Bonding

The reactions of paddlewheel-type II) complexes, [Ru2(II,II)(x-FPhCO2)(4)(THF)(2)] (x-FPhCO2- =x-fluorobenioate with x- = 0(-),m(-),p(-)), With 2,6- diaminopyridine (dapy) and 7-azaindole (azain) afford axially capped discrete compounds, [Ru-2(II,II)(x-FPhCO2)(4)(dapy)(2)] (x o-, 1; m-, 2; p-, 3) and [Ru-2(II,II)(o-FPhCO2)(4)(azain)(2)] (4), respectively. In these compounds, intramolecular hydrogen bonds are observed between NH2 groups for 173 or imine NH2 groups for 4 and oxygen atoms of Carboxylate groups. In addition, hydrogen bonds of. NH2...F are also observed for 1 and 4 with an o-positioned F atom on benzoate. This coordination mode, i.e., a dual bonding mode with a-bonding and hydrogen bonding, should assist ligand coordination to the axial position of the [Ru-2] unit The Ru-N bond distance in 1-4 is shorter than that observed in related compounds reported previously. In a similar fashion, reactions with planar M-II dithiobiuret complexes, [M-II(dtb)(2)] (M-II = Pd-II and Pt-II), were carried out One-dimensional alternating chains, [{Ru-2(II,II)(o- :FFhCO(2))(4)}{M-II(dtb)(2)}] (M-II = Pd-II, 5; Pt-II, 6), were obtained, in which the hydrogen bonding modes of NH2...O and NH2...F are present, as expected, DFT calculations for the [M-II(dtb)(2)] Unit revealed that the LUMO of [M-II(dtb)(2)] lies at -2.159 and -1.781 eV for M = Pd and Pt, respectively, which is much higher than HOMO 'energy at -4.184 eV calculated for [Ru-2(II,II)(o-FPhCO2)(THF)(2)], proving that the respective units are essentially electronically isolated in the chains.