RESUMO
The N-heterocyclic carbene (NHC) precursor, 1-(2-aminoethyl)-3-methylimidazolium nitrate, [NH(2)(CH(2))(2)imMe)]NO(3) ([3][NO(3)]) reacted with Ag(2)CO(3) in dimethyl sulfoxide readily yielding a Ag(I)-(NHC-NH(2)) complex presenting limited stability in solution. The in situ carbene transfer reaction of the latter with [Au(tht)Cl] afforded the first example of a dinuclear gold(I) complex [Au(2)(NH(2)(CH(2))(2)imMe)(2)][NO(3)](2) ([5][NO(3)](2)) bearing a primary amino-functionalized NHC ligand. The complex has been characterized by NMR, mass spectrometry, X-ray crystallography and cyclic voltammetry; the electrochemical behaviour and photophysical properties of [5][NO(3)](2) have been also investigated and the experimental data have been compared with density functional theory (DFT) and Time Dependent (TDDFT) calculations. Single-crystal structural studies showed that the Au(I)-carbene compound contains dinuclear (AuL)(2) cations in which pairs of gold(I) centres are linked by a pair of bridging ligands, with a Au···Au aurophilic contact of 3.2332(17) Å that is maintained in solution as documented by the DFT calculations. Complex [5][NO(3)](2) is photoluminescent in solution at room temperature and the high energy emission peak at 410 nm is remarkably shifted with respect to the absorption band centered at 260 nm.
RESUMO
The vinyliminium complex [Fe2{mu-eta(1):eta(3)-C(SiMe3)=CHC=N(Me)2}(mu-CO)(CO)(Cp)2][SO3CF3] reacts with HC[triple bond]CR (R = CPh2OH), affording a mixture of the 2,4,6-trisubstituted oxo-eta(5)-cyclohexadienyl complex [Fe{eta(5)-C6H2O(NMe2)(SiMe3)(R)}(Cp)], the 2,6-disubstituted phenol C6H3R(NMe2)OH (R = CHPh2) and 1,2,4-trisubstituted ferrocene [1-NMe2-2-R-4-SiMe3-Fc]. The corresponding reaction with HC[triple bond]CR (R = CMe2OH) yields analogous products: [Fe{eta(5)-C6H2O(NMe2)(SiMe3)(R')}(Cp)] (R' = CMe=CH2), the phenol C6H3R'(NMe2)OH together with [1-NMe2-2-R-4-SiMe3-Fc].
Assuntos
Alcinos/química , Monóxido de Carbono/química , Compostos Ferrosos/química , Compostos Ferrosos/síntese química , Cristalografia por Raios X , Ciclização , Ligantes , Modelos Moleculares , Estrutura MolecularRESUMO
The reaction between [Rh[C5H4CO2(CH)2OH](NBD)] (1) and 1,1'-carbonyldiimidazole (CDI) leads to the new CO2-imidazole functionalized alkoxycarbonylcyclopentadienyl complex [Rh[C5H4CO2(CH2)2O2C-Im](NBD)] (2) (Im=imidazole). The latter was treated with five generations of poly(propylenimine) dendrimers DAB-dendr-(NH2)(n) [n=4, 8, 16, 32, 64] (DAB=diaminobutane) to accomplish the synthesis of the new organometallic dendritic macromolecules DAB-dendr-[NH(O)COCH2CH2OC(O)C5H4Rh(NBD)](n) [n=4 (4), 8 (5), 16 (6), 32 (7), 64 (8)] based on flexible poly(propylenimine) dendrimer cores, built up to the fifth generation. Spectroscopic characterization of all the new compounds will be presented and discussed.