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Synthesis of the perfluorinated 1,3,5-triazapentadiene [N{(CF3)C(C6F5)N}2]H and the use of its conjugate base as a supporting ligand for the isolation of silver(i) and copper(i) complexes are reported. Some of the related chemistry involving [N{(C3F7)C(C6F5)N}2]−(that has bulkier –C3F7groups on the 1,3,5-triazapentadienyl ligand backbone) is also presented. X-ray crystallographic data show a wide variety of structures ranging from intermolecular, hydrogen-bonded chain structure for [N{(CF3)C(C6F5)N}2]H with a twisted W-shaped N3C2core, monomeric [N{(CF3)C(C6F5)N}2]Ag(CNtBu)2and [N{(C3F7)C(C6F5)N}2]Ag(CNtBu)2where the κ1-bonded triazapentadienyl ligand bonding to the metal fragment viathe central nitrogen atom, monomeric [N{(CF3)C(C6F5)N}2]Ag(PPh3)2and [N{(C3F7)C(C6F5)N}2]Ag(PPh3)2that feature κ1-bonded triazapentadienyl ligand bonding to the metal fragment viaone of the terminal nitrogen atoms, to that of the monomeric [N{(CF3)C(C6F5)N}2]Cu(CNtBu)2containing a κ2-bonded triazapentadienyl ligand and a U-shaped NCNCN ligand backbone. The isocyanide adducts show relatively high νCNvalues in the IR spectra. [ABSTRACT FROM AUTHOR]

Copper and silver carbonyl and ethylene adducts supported by the highly fluorinated hydridotris(triazolyl)borate ligand [HB(3,5-(CF3)2Tz)3]−have been synthesized and characterized, and compared to the analogous complexes based on the hydridotris(pyrazolyl)borate ligand [HB(3,5-(CF3)2Pz)3]−. 1H and 13C NMR signals of the ethylene moiety of [HB(3,5-(CF3)2Tz)3]Cu(C2H4) and [HB(3,5-(CF3)2Tz)3]Ag(C2H4) appear at a relatively downfield position from the corresponding signals of the [HB(3,5-(CF3)2Pz)3]Cu(C2H4) and [HB(3,5-(CF3)2Pz)3]Ag(C2H4) complexes. This indicates the presence of relatively acidic metal sites in the [HB(3,5-(CF3)2Tz)3]−supported molecules. [HB(3,5-(CF3)2Tz)3]−is also a relatively weaker donor compared to the tris(pyrazolyl)borate version [HB(3,5-(CF3)2Pz)3]−. However, the CO stretching frequency values of [HB(3,5-(CF3)2Tz)3]CuCO (2138 cm−1) and [HB(3,5-(CF3)2Pz)3]CuCO (2137 cm−1) are essentially identical, and did not reflect the differences in the acidity of the metal sites. The analogous silver carbonyl adducts [HB(3,5-(CF3)2Tz)3]AgCO and [HB(3,5-(CF3)2Pz)3]AgCO also show similar νCOvalues (2178 cm−1). These results illustrate the limitation of using the νCOvalue of metal carbonyls as a sole indicator of the electronic structure of metal sites in some metal complexes, especially when the metal→CO π-back bonding is less important, and the νCOvalues of two adducts are unexpectedly similar and appear at a region closer to that of the free CO (2143 cm−1). [ABSTRACT FROM AUTHOR]

Data from computational and experimental sources have been combined to address the bonding and structure of [RB(3-(R1),5-(R2)Pz)3]M(C2H4) complexes, where M = Cu, Ag, Au. A κ3to κ2distortion of the scorpionate ligand was also studied. NMR properties were deemed to be the most useful in assessing the nature of the bonding in these complexes. Using computational recipes, 13C chemical shifts accurately reproduced quantitative experimental values and trends as a function of metal, ligand, and substituent. Au−ethylene complexes are found to be substantially “less π-complex” (T-shaped structure) in their bonding description versus Ag and Cu congeners, although the former are by no means entirely metallacyclopropane in their constitution. Combining the present calculations with prior contributions to coinage metal bonding leads us to propose that similarity of molecular structure among a congeneric series of coinage metal complexes reflects a principally ionic coinage metal−ligand bonding regime, while dissimilarity of structure within the series reflects a primarily covalent bonding regime. [ABSTRACT FROM AUTHOR]

Halogenated 1,3,5-triazapentadienyl ligands [N{(C3F7)C(C6F5)N}2]−, [N{(CF3)C(C6F5)N}2]−and [N{(C3F7)C(2,6-Cl2C6H3)N}2]−, alone or in combination with other N-donors like CH3CN, CH3(CH2)2CN, and N(C2H5)3, have been used in the stabilization of thermally stable, two-, three- or four-coordinate silver(i) adducts. X-Ray crystallographic analyses of {[N{(C3F7)C(C6F5)N}2]Ag}n, {[N{(C3F7)C(C6F5)N}2]Ag(NCCH3)}n, {[N{(C3F7)C(2,6-Cl2C6H3)N}2]Ag(NCCH3)}n, {[N{(CF3)C(C6F5)N}2]Ag(NCCH3)2}nand {[N{(C3F7)C(C6F5)N}2]Ag(NCC3H7)}nrevealed the presence of bridging 1,3,5-triazapentadienyl ligands bonded to silver through terminal nitrogen atoms. These adducts are polymeric in the solid state. [N{(C3F7)C(2,6-Cl2C6H3)N}2]AgN(C2H5)3is monomeric and features a 1,3,5-triazapentadienyl ligand bonded to Ag(i) in a κ1-fashion viaonly one of the terminal nitrogen atoms. The solid state structure of [N{(C3F7)C(C6F5)N}2]H has also been reported and it forms polymeric chains viainter-molecular N–HN hydrogen-bonding. [ABSTRACT FROM AUTHOR]

The first total synthesis of the Leucettaalkaloid calcaridine A is described based on a biosynthetic postulate. Application of an oxidative rearrangement of a 4,5-disubstituted imidazole leads to the formation of both calcaridine A and epi-calcaridine A. An X-ray crystal structure determination on the latter has allowed the assignment of the relative configuration of the epimeric natural product and calcaridine A by extrapolation. [ABSTRACT FROM AUTHOR]

The interactions present in cyclic trinuclear coinage metal pyrazolates were studied computationally. Cuprophilic interaction was found to bind the singlet ground state of the dimer of trimers Cu(Pz)32, overcoming electrostatic repulsion. The large variation in intertrimer separations found in the literature for coinage metal pyrazolates is consistent with the relatively weak metallophilic interaction. The emissive triplet excited-state geometry of M(Pz)32is predicted by density functional calculations to show major geometric distortion caused by Jahn−Teller instability and excimeric M−M bonding. Large calculated Stokes' shifts, which are also observed for experimental models, are consistent with significant excited-state distortions for these materials. The major finding derived from the present study is that the intertrimer M···M contraction in the emissive T1state is much more than the intratrimer contraction in all M(Pz)32models, giving rise to a lower T1→ S0phosphorescence energy in these models than in analogous monomer-of-trimer models. The observations made here point to a great potential for rationally tuning the emission properties of trinuclear coinage metal complexes through choice of the metal and ligands. [ABSTRACT FROM AUTHOR]

Three closely related organometallic “spoke–wheel” complexes featuring coinage metal ions, Au(i), Ag(i), and Cu(i), bonded to three norbornene molecules in trigonal planar fashion have been isolated and completely characterized using several methods including X-ray crystallography. [ABSTRACT FROM AUTHOR]

Cationic bis(alkyne)copper(I) carbonyland bis(alkyne)copper(I)isocyanide complexes have been synthesized from the precursor (cyclooctyne)2CuBr. [Cu(cyclooctyne)2(CO)][SbF6] and [Cu(cyclooctyne)2(CNtBu)][SbF6] have trigonal-planar and three-coordinate copper centers. The coppercarbonyl complex [Cu(cyclooctyne)2(CO)][SbF6] displays its C–O stretching frequency in the “nonclassical”metal carbonyl region (2171 cm–1), and the analogouscopper(I) isocyanide complex [Cu(cyclooctyne)2(CNtBu)][SbF6] also has an unusually high CN stretching bandat 2230 cm–1. The reaction of 3,5-Me2C6H3NH2and 4-tBuC6H4NH2with [Cu(cyclooctyne)2(CO)][SbF6] led to CO displacement rather than additionto CO. CNtBu reacts with [Cu(cyclooctyne)2(CO)][SbF6] to afford [Cu(cyclooctyne)2(CNtBu)][SbF6]. The syntheses of [Cu(cyclooctyne)(CNtBu)2][SbF6] and [Cu(CNtBu)4][SbF6] from the (cyclooctyne)2CuBr precursor are alsoreported. [ABSTRACT FROM AUTHOR]

The copper(i) ethylene complex [N{(C3F7)C(Dipp)N}2]Cu(C2H4) (Dipp = 2,6-diisopropylphenyl) has been synthesized by treating [N{(C3F7)C(Dipp)N}2]Cu(NCCH3) with ethylene at room temperature. [N{(C3F7)C(Dipp)N}2]Cu(C2H4) is an air stable, yellow solid. X-Ray crystallographic data of [N{(C3F7)C(Dipp)N}2]Cu(C2H4) show that the 1,3,5-triazapentadienyl ligand coordinates to copper in κ2-fashion. The copper atom adopts a trigonal-planar geometry. [N{(C3F7)C(Dipp)N}2]Cu(C2H4) and [N{(C3F7)C(Dipp)N}2]Cu(NCCH3) effectively catalyze carbene and nitrene transfer to a variety of substrates in high efficiencies. [ABSTRACT FROM AUTHOR]

Two rare copper complexes, a tri-alkene adduct [Cu(ttt-cdt)(FSbF5)] and a non-classical carbon monoxide complex [Cu(ttt-cdt)(CO)][SbF6] with a high CO stretching frequency (CO= 2160 cm−1), have been isolated using trans,trans,trans-1,5,9-cyclododecatriene (ttt-cdt) ligand. [ABSTRACT FROM AUTHOR]

Fluorinated tris(triazolyl)borate [HB(3,5-(CF3)2Tz)3]−(Tz = triazolyl) affords the isolation of [Na(THF)6]{[HB(3,5-(CF3)2Tz)3]2Na} with a ligand sandwiched sodium ion and a copper carbonyl complex [HB(3,5-(CF3)2Tz)3]CuCO with a high C–O stretching frequency. [ABSTRACT FROM AUTHOR]

A silver(i) complex derived from a polyfluorinated tris(pyrazolyl)borate effectively catalyzes carbene transfer to allylic and propargylic halides, leading to the formation of α-haloacetate derivatives. [ABSTRACT FROM AUTHOR]