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Iron(0) pentacarbonyl is an organometallic compound with a long history. It undergoes carbonyl displacement chemistry with various donors (L), leading to molecules of the type Fe(CO)x(L)5–x. The work reported here illustrates that Fe(CO)5 can also act as a ligand. The reaction between Fe(CO)5 with the silver salts AgSbF6 and Ag[B{3,5-(CF3)2C6H3}4] under appropriate conditions resulted in the formation of [(μ-H2O)AgFe(CO)5]2[SbF6]2 and [B{3,5-(CF3)2C6H3}4]AgFe(CO)5, respectively, featuring heterobimetallic {Ag–Fe(CO)5}+ fragments. The treatment of [B{3,5-(CF3)2C6H3}4]AgFe(CO)5 with 4,4′-dimethyl-2,2′-bipyridine (Me2Bipy) and Fe(CO)5 afforded a heterobimetallic [(Me2Bipy)AgFe(CO)5][B{3,5-(CF3)2C6H3}4] species with a Ag–Fe(CO)5 bond and a heterotrimetallic [{Fe(CO)5}2(μ-Ag)][B{3,5-(CF3)2C6H3}4] with a (CO)5Fe–Ag–Fe(CO)5 core, respectively, illustrating that it is possible to manipulate the coordination sphere at silver while keeping the Ag–Fe bond intact. The chemistry of [B{3,5-(CF3)2C6H3}4]AgFe(CO)5 with E...

Iron(0) pentacarbonyl is an organometallic compound with a long history. It undergoes carbonyl displacement chemistry with various donors (L), leading to molecules of the type Fe(CO)

Synthetic details, solid-state structures, and photophysical properties of a group of trimeric copper(I) complexes containing pyrazolate ligands are described. The reaction of copper(I) oxide and the fluorinated pyrazoles [3-(CF(3))Pz]H, [3-(CF(3)),5-(Me)Pz]H, and [3-(CF(3)),5-(Ph)Pz]H leads to the corresponding trinuclear copper(I) pyrazolates, {[3-(CF(3))Pz]Cu}(3), {[3-(CF(3)),5-(Me)Pz]Cu}(3), and {[3-(CF(3)),5-(Ph)Pz]Cu}(3), respectively, in high yield. The {[3,5-(i-Pr)(2)Pz]Cu}(3) compound was obtained by a reaction between [Cu(CH(3)CN)(4)][BF(4)], [3,5-(i-Pr)(2)Pz]H, and NEt(3). These compounds as well as {[3,5-(Me)(2)Pz]Cu}(3) and {[3,5-(CF(3))(2)Pz]Cu}(3) adopt trimeric structures with nine-membered Cu(3)N(6) metallacycles. There are varying degrees and types of intertrimer Cu...Cu interactions. These contacts give rise to zigzag chains in the fluorinated complexes, {[3-(CF(3))Pz]Cu}(3), {[3-(CF(3)),5-(Me)Pz]Cu}(3), {[3-(CF(3)),5-(Ph)Pz]Cu}(3), and {[3,5-(CF(3))(2)Pz]Cu}(3), whereas the nonfluorinated complexes, {[3,5-(Me)(2)Pz]Cu}(3) and {[3,5-(i-Pr)(2)Pz]Cu}(3) form dimers of trimers. Out of all the compounds examined in this study, {[3-(CF(3)),5-(Ph)Pz]Cu}(3) has the longest (3.848 Angstroms) and {[3,5-(Me)(2)Pz]Cu}(3) has the shortest (2.946 Angstroms) next-neighbor intertrimer Cu...Cu distance. The Cu...Cu separations within the trimer units do not vary significantly (typically 3.20-3.26 Angstroms). All of these trinuclear copper(I) pyrazolates show bright luminescence upon exposure to UV radiation. The luminescence bands are hugely red-shifted from the corresponding lowest-energy excitations, rather broad, and unstructured even at low temperatures, suggesting metal-centered emissions owing to intertrimer Cu...Cu interactions that are strengthened in the phosphorescent state. The {[3-(CF(3)),5-(Ph)Pz]Cu}(3) compound exhibits an additional highly structured phosphorescence with a vibronic structure corresponding to the pyrazolyl (Pz) ring. The luminescence properties of solids and solutions of the trimeric compounds in this study show fascinating trends with dramatic sensitivities to temperature, solvent, concentration, and excitation wavelengths.

The neutral and cationic aminotroponiminate derivatives of germanium(II) have been investigated. The treatment of GeCl2·(1,4-dioxane) with [(i-Pr)2ATI]Li or [(Me)2ATI]Li in a 1:1 molar ratio gave the corresponding monochloro germanium(II) complex. Substitution of the chloride ion of [(i-Pr)2ATI]GeCl with weakly coordinating anions [CF3SO3]- and [(η5-C5H5)ZrCl2(μ-Cl)3ZrCl2(η5-C5H5)]- led to cationic germanium(II) species containing {[(i-Pr)2ATI]Ge}+ ion. Although NMR data of the cationic species show notable differences relative to their neutral analog, the solid state data show only minor changes in the C7N2Ge moiety. The Ge−N bond distances of the cations are not indicative of significant Ge−N π-bonding. These compounds feature some of the smallest N−Ge−N angles known for Ge(II) compounds. Attempted synthesis of the tetraphenylborate salt of {[(Me)2ATI]Ge}+ led to a phenyl group transfer product [(Me)2ATI]GePh·BPh3 with a Ge(II)−B bond. Details of the 1H, 13C NMR spectroscopy and X-ray crystal structures...

Organoazides and their nitrogen expulsion chemistry have attracted the attention of many scientists because they serve as a useful source of nitrene fragments and interesting nitrene rearrangement products. Gold-mediated reactions are also of significant current interest. This manuscript describes several important discoveries based at the intersection of these fields. In particular, we report the first isolable gold organoazides ([(SIPr)AuN(1-Ad)NN][SbF6], [(SIPr)AuN(2-Ad)NN][SbF6] and [(SIPr)AuN(Cy)NN][SbF6]; SIPr = a N-heterocyclic carbene; 1-AdNNN = 1-azidoadamantane; 2-AdNNN = 2-azidoadamantane; CyNNN = azidocyclohexane), and their gold-mediated nitrogen expulsion chemistry, and the isolation of formal nitrene rearrangement products of "1-AdN", "2-AdN" and "CyN" (including the elusive 4-azahomoadamant-3-ene) as their gold complexes. We have also performed a computational study to understand and explain the observed structure of gold-coordinated 1-AdNNN and 2-AdNNN and their nitrogen elimination pathways, which implies that the conversion of the organoazide complex to the imine is a concerted process without a nitrene/nitrenoid intermediate. Kinetic studies of [(SIPr)AuN(2-Ad)NN][SbF6] from 30 to 50 °C indicate that nitrogen elimination is a first-order process. The experimentally determined activation parameters are in good agreement with the calculated values.

The compounds [(i-Pr)2ATI]SnCl (1) and {[(i-Pr)2ATI]Sn}[η5-C5H5)ZrCl2(μ-Cl3)ZrCl2(η5-C5H5)] (2) in which [(i-Pr)2ATI] = N-isopropyl-2-(isopropylamino)troponimine have been prepared and characterized by 1H, 13C, and 119Sn NMR spectroscopies and X-ray crystallography. Compounds 1 and 2 feature heterobicyclic C7N2Sn ring systems with basically three- and two-coordinate tin atoms, respectively. Solid state structures of 1 and 2 show weak Sn···Cl interactions. The 119Sn NMR signal of 2 appears at a significantly lower field compared to that of 1. This is consistent with the reduction in coordination number at the Sn center of 2. The 1H NMR data also provide evidence for the formation of a more symmetric solution species with the removal of Cl- from 1. X-ray structural features of C7N2Sn moiety in [(i-Pr)2ATI]SnCl and the {[(i-Pr)2ATI]Sn}+ cation are very similar. The Sn−N bond distances of {[(i-Pr)2ATI]Sn}+ cation are not indicative of any significant Sn−N multiple bonding. The π-electrons of the C7N2Sn ring s...

The synthesis and characterization of the stable carbene perdeuterio-1,3,4,5-tetramethylimidazol-2-ylidene (2) are reported. The neutron and X-ray diffraction data from single crystals of this perdeuterocarbene are used to determine the electron distribution in the molecule. Neutron diffraction data were collected at 80 and 173K on 2. The experimentally determined electron density is very closely matched by density functional calculations which show that 2 is a true carbene with negligible ylidic character. 71 refs., 6 figs., 5 tabs.

A series of thermally stable, easily isolable, monomeric, and isoleptic coinage metal alkyne complexes have been reported. Treatment of [N{(C(3)F(7))C(Dipp)N}(2)]Li (the lithium salt of the 1,3,5-triazapentadiene [N{(C(3)F(7))C(Dipp)N}(2)]H) with AuCl, CF(3)SO(3)Ag or CF(3)SO(3)Cu in the presence of 3-hexyne led to the corresponding coinage metal alkyne complex [N{(C(3)F(7))C(Dipp)N}(2)]M(EtC[triple bond]CEt) in good yield (M = Au, Ag, Cu; Dipp = 2,6-diisopropylphenyl). X-ray crystal structures of the three coinage metal alkynes are remarkably similar, and show the presence of trigonal-planar metal sites with eta(2)-bonded 3-hexyne. The M-C and M-N bond distances vary in the order CuAuAg. The bending of the C-C[triple bond]C bond angle is largest for the gold, followed by Cu and Ag adducts. The gold adduct also shows the largest decrease in C[triple bond]C stretching frequency in Raman, while the Ag adduct shows the smallest change compared to that of the uncoordinated alkyne. DFT calculations on [N{(CF(3))C(Ph)N}(2)]M(EtC[triple bond]CEt) and the related ClM(EtC[triple bond]CEt) predict that the M-alkyne bond energy varies in the order AgCuAu. The gold adducts are also predicted to have the longest C[triple bond]C, largest deviation of C-C[triple bond]C bond angle from linearity, and smallest C[triple bond]C stretching frequency, followed by the Cu and Ag adducts. In these triazapentadienyl coinage metal adducts, the sigma-donation from alkyne --M dominates over the M --alkyne pi-back-donation.

A photophysical study is reported for the trinuclear copper(I) complex {[3,5-(CF3)2Pz]Cu}3. The neutral compound exhibits multicolor bright phosphorescent emissions both in the solid state and in solution. The emission can be tuned to multiple visible colors by controlling the temperature, solvent, and {[3,5-(CF3)2Pz]Cu}3 concentration, giving rise to luminescence thermochromism, luminescence solvatochromism, and a new optical phenomenon called "concentration luminochromism", respectively.

The silver complex [HB(3,5-(CF3)2Pz)3]Ag(THF) featuring a highly fluorinated tris(pyrazolyl)borate ligand catalyzes the formation of aliphatic carbon-halogen bond activation products under remarkably mild conditions. For example, the reaction between CHCl3 and ethyl diazoacetate (EDA) at room temperature in the presence of the silver catalyst afforded HClC(CO2Et)CCl2H in 60% yield. The presence of beta-hydrogens on the alkyl halide leads to net hydrogen halide addition to the carbene and an alkene.

[Li(12-crown-4)NPh 2 ], [{LiEt 2 O) 2 AsPh 2 } 2 ], [Li(12-crown-4) 2 ] [Sb 3 Ph 4 ]•THF cristallisent dans le systeme monoclinique, groupe d'espace C2 /c et leur structure est affinee respectivement jusqu'a R=0,043; R=0,053 et R=0,056. [Li(1,4-dioxane) 3 AsPh 2 ] cristallise dans P2 1/c avec R=0,063. [Li(12-crown-4) 2 ] [SbPh 2 ]•1/3 THF cristallise dans le systeme triclinique, groupe d'espace P1 avec R=0,084