Terminal Ligand (L) Effects on Zero-Magnetic-Field Splitting in the Excited Triplet States of [{MoBr}L] (L = Aromatic Carboxylates).

We report the emission properties of the octahedral hexamolybdenum(II) bromide-core ({MoBr}) clusters having a series of terminal aromatic carboxylate ligands (RCOO), [{MoBr}(RCOO)], in solution and crystalline phases. The acid dissociation constant of RCOOH (p K(L)) was shown to govern the redox and emission properties of the clusters. Temperature ( T)-controlled emission experiments (3-300 K) demonstrated that the clusters showed large T-dependent emission energies (ν̃) and lifetimes (τ) because of zero-magnetic-field splitting in the emissive excited triplet (T) states.

Quasi-One-Step Six-Electron Electrochemical Reduction of an Octahedral Hexanuclear Molybdenum(II) Cluster.

We report for the first time quasi-one-step six-electron electrochemical reduction of a new hexanuclear molybdenum(II) bromide cluster having terminal 3,5-dinitrobenzoate ligands: [MoBr(DNBA)]. The electrochemical responses of the cluster were studied based on cyclic (CV), differential pulse, and normal pulse voltammetries, together with the analytical simulations of the CV and spectroelectrochemistry. CV simulations have revealed that the electrochemical reaction of the cluster proceeds in an EEEEEE scheme, and the potential differences between the two adjacent reduction steps are in the range of 15-30 mV.