Carbide complexes as π-acceptor ligands.

The π-accepting character of a terminal carbide complex acting as a ligand is demonstrated experimentally and corroborates earlier theoretical predictions. As a result, coordination of a terminal ruthenium carbide complex to electron-rich metal centres is shown to provide a facile and versatile route to carbide-bridged heterometallic complexes. Synthesis, reactivity, spectroscopic and structural characterization are reported for heterobimetallic systems with auxiliary metals from groups : Rh(i), Ir(i), Pd(ii), Pt(ii), Ag(i), and Au(i) coordinated by [Ru(C)Cl(PCy)] ().

Fluoride-bridged {Ln2Cr2} polynuclear complexes from semi-labile mer-[CrF3(py)3] and [Ln(hfac)3(H2O)2].

The trifluorido complex mer-[CrF(3)(py)(3)] (py = pyridine) reacts with 1 equiv. of [Ln(hfac)(3)(H(2)O)(2)] and depending on the solvent forms the tetranuclear clusters [Cr(2)Ln(2)(μ-F)(4)(μ-OH)(2)(py)(4)(hfac)(6)], 1Ln, and [Cr(2)Ln(2)(μ-F)(4)F(2)(py)(6)(hfac)(6)], 2Ln, in acetonitrile and 1,2-dichloroethane, respectively (Ln = Y, Gd, Tb, Dy, Ho, and Er; hfacH = 1,1,1,5,5,5-hexafluoroacetylacetone). Reaction with [Dy(hfac)(3)(H(2)O)(2)] in dichloromethane produces the dinuclear cluster [CrDy(μ-F)F(OH(2))(py)(3)(hfac)(4)], 3Dy.

A bis(heptafulvenyl)-dicyanoethylene thermoswitch with two sites for ring closure.

Suitably functionalized vinylheptafulvenes (VHFs) act as thermoswitches undergoing ring closure to the corresponding dihydroazulenes (DHAs). Here we present the synthesis of a new such thermoswitch incorporating two heptafulvene rings on a dicyanoethylene unit. The synthetic protocol explores both the tropylium species as an electrophile and as a leaving group in the generation of the heptafulvene units.

Bond shortening (1.4 Å) in the singlet and triplet excited states of [Ir2(dimen)4]2+ in solution determined by time-resolved X-ray scattering.

Ground- and excited-state structures of the bimetallic, ligand-bridged compound Ir2(dimen)4(2+) are investigated in acetonitrile by means of time-resolved X-ray scattering. Following excitation by 2 ps laser pulses at 390 nm, analysis of difference scattering patterns obtained at eight different time delays from 250 ps to 300 ns yields a triplet excited-state distance between the two Ir atoms of 2.90(2) Å and a triplet excited-state lifetime of 410(70) ns.

Synthesis and molecular structure of Cr(salen)(mu-N)RhCl(COD): the first example of a heterobimetallic nitride-bridged complex containing chromium.

Five-coordinate Cr(N)(salen) {salen is 2,2'-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolate} reacts with [RhCl(COD)](2) (COD is 1,5-cyclooctadiene) to yield the heterobimetallic nitride-bridged title compound, namely chlorido-2kappaCl-[2(eta(4))-1,5-cyclooctadiene]{2,2'-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato-1kappa(4)O,N,N',O'}-mu-nitrido-1:2kappa(2)N:N-chromium(V)rhodium(I), [CrRh(C(16)H(14)N(2)O(2))ClN(C(8)H(12))]. The Cr-N bond of 1.5936 (14) A is elongated by only 0.