Multifunctional one-dimensional rhodium(I)-semiquinonato complex: substituent effects on crystal structures and solid-state properties.

Two new one-dimensional (1D) rhodium(I)–semiquinonato complexes formulated as [Rh(3,6-DBSQ-4,5-PDO)(CO)2]∞ (4; 3,6-DBSQ-4,5-PDO•– = 3,6-di-tert-butyl-4,5-(1,3-propanedioxy)-1,2-benzosemiquinonato) and [Rh(3,6-DBSQ-4,5-(N,N′-DEN))(CO)2]∞ (5; 3,6-DBSQ-4,5-(N,N′-DEN)•– = 3,6-di-tert-butyl-4,5-(N,N′-diethylenediamine)-1,2-benzosemiquinonato) were synthesized to explore the nature of the unusual structural phase transition and magnetic and conductive properties recently reported for [Rh(3,6-DBSQ-4,5-(MeO)2)(CO)2]∞ (3; 3,6-DBSQ-4,5-(MeO)2•– = 3,6-di-tert-butyl-4,5-dimethoxy-1,2-benzosemiquinonato). Their crystal structures and magnetic and conductive properties were investigated. Compounds 4 and 5 comprise neutral 1D chains of complex molecules stacked in a staggered arrangement with fairly short average Rh–Rh distances of 3.06 A for 4 and 3.10 A for 5. These distances are similar to those for 3 (3.09 A); however, the molecules of 5 are strongly dimerized in the 1D chain. Compound 4 undergoes a first-order phas...