Two- and three-dimensional assembled structures constructed from amidate-bridged paddlewheel complexes with group 6 oxometallate ions

Magnetostructural Studies on Zigzag One-Dimensional Coordination Polymers Formed by Tetraamidatodiruthenium(II,III) Paddlewheel Units Bridged by SCN Ligands

We report herein on three zigzag one-dimensional coordination polymers of {[Ru2(μ-NHOCR)4](μ-SCN)}n (R = o-Me-C6H4 (2), m-Me-C6H4 (3), p-Me-C6H4 (4)) formula. These new compounds have been obtained by reaction of the corresponding [Ru2(μ-NHOR)4(THF)2](BF4) complex with (NBu4)(SCN) under different synthetic conditions. The crystal structure of [Ru2(μ-NHOCC6H4-o-Me)4(THF)2](BF4) (1), 2 and 3 are presented. A cis-(2,2) arrangement of the amidate ligands of the [Ru2(μ-NHOCR)4]+ units is observed in all cases. Interestingly, the structures of 2 and 3 show linkage isomerism in alternated tetraamidatodiruthenium units whose axial positions are occupied by the same type of donor atom of the SCN ligands. This results in zigzag chains with a Ru-S-C angle of 98.97° and Ru-N-C angle of 169.36° in the case of 2 and 97.99° and 159.26°, respectively, in the case of 3. The magnetic data obtained for 2–4 are indicative of a σ2π4δ2(π*δ*)3 ground state (S = 3/2) and a large zero-field splitting (ZFS) in all cases (D = 54.57, 62.72 and 43.00 cm−1 for 2–4, respectively). Similar small antiferromagnetic interactions between diruthenium units (zJ = −0.93, −0.79 and −1.11 cm−1 for 2–4, respectively) are estimated for all the polymers, suggesting an analogous zigzag arrangement of the chains for 4.

Assembled structures of tetrakis(biimidazole)dirhodium complexes hydrogen-bonded with common inorganic anions

Eight new structures of dirhodium complexes, each with four biimidazole (H2bim) ligands, were obtained: [Rh2(H2bim)4(H2O)2](NO3)4·4H2O (I), [Rh2(H2bim)4(H2O)2](ClO4)4·5H2O (II), [Rh2(H2bim)4(MeOH)2](ClO4)4 (III), [Rh2(H2bim)4(DMF)2](BF4)4 (IV), [Rh2(H2bim)4(Mepy)2](SiF6)2·8H2O (V), [{Rh2(H2bim)4(pz)}2(μ-pz)](SiF6)(ClO4)6·12.7H2O (VI), [{Rh2(H2bim)4(pz)}2(μ-pz)](ClO4)8·11.4H2O (VII) and [Rh2(H2bim)4(μ-pz)](SiF6)2·6H2O (VIII). The unbridged Rh-Rh bond distances range between 2.6313 (8) and 2.7052 (5) Å. The dirhodium units adopt a staggered conformation with torsion angles N-Rh-Rh-N of 37.6 (4)-48.98 (8)°. Various assembled structures were constructed by hydrogen bonding between the complexes and the anions: a discrete structure in (IV), one-dimensional structure in (II), two-dimensional structures in (I), (III), (VI), (VII) and (VIII) and a three-dimensional structure in (V).