Adduct formation or metathesis reactions of silver complexes containing the fluorinated ligands [HB(3,5-(CF3)2Pz)3]- and [CF3SO3]-: formation of silver adducts containing unsupported silver-germanium bonds

A mixture of [HB(3,5-(CF3)2Pz)3]Ag(eta 2-toluene) and [(Me)2ATI]GeCl in CH2Cl2, rather than undergoing metathesis, formed a 1:1 adduct [HB(3,5-(CF3)2Pz)3]Ag<--GeCl[(Me)2ATI] (1, where [HB(3,5-(CF3)2Pz)3] = hydrotris(3,5-bis(trifluoromethyl)pyrazolyl)borate and [(Me)2ATI] = N-methyl-2-(methylamino)troponiminate) featuring a silver-germanium bond. Solutions of 1 (in CH2Cl2 or toluene) did not precipitate AgCl even after several days. However, it easily underwent metathesis with CF3SO3Ag, leading to the chloride-free product [HB(3,5-(CF3)2Pz)3]Ag<--Ge(OSO2CF3)[(Me)2ATI] (2). Compounds 1 and 2 were characterized by X-ray crystallography. The Ag-Ge bond distances of 1 and 2 are 2.4215(9) and 2.4116(10) A, respectively.     

Fluorinated tris(pyrazolyl)borate ligands without the problematic hydride moiety: isolation of copper(I) ethylene and copper(I)-tin(II) complexes using [MeB(3-(CF3)Pz)3]-

The thallium derivative of a fluorinated, B-methylated, tris(pyrazolyl)borate ligand, [MeB(3-(CF3)Pz)3]-, has been synthesized via a two-step process using the corresponding pyrazole, Li[MeBH3], and thallium(I) acetate. Reaction of [MeB(3-(CF3)Pz)3]Tl with CuBr in the presence of ethylene leads to [MeB(3-(CF3)Pz)3]Cu(C2H4). It is a thermally stable solid. [MeB(3-(CF3)Pz)3]Cu(C2H4) reacts with [(Bn)2ATI]SnCl to yield [MeB(3-(CF3)Pz)3]Cu<--Sn(Cl)[(Bn)2ATI], featuring an unsupported Cu(I)-Sn(II) bond [2.4540(4) A].     

Syntheses of aluminum and zinc alkyl complexes of a highly fluorinated tris(pyrazolyl)borate using [HB(3,5-(CF3)2Pz)3]Ag(THF) as the ligand transfer agent

Dimethylaluminum or ethylzinc complexes of highly fluorinated tris(pyrazolyl)borate ligand [HB(3,5-(CF(3))(2)Pz)(3)](-) can be obtained in excellent yield from the reaction between the silver adduct [HB(3,5-(CF(3))(2)Pz)(3)]Ag(THF) and the metal alkyl reagent Me(3)Al or Et(2)Zn. The X-ray crystal structure of [HB(3,5-(CF(3))(2)Pz)(3)]AlMe(2) shows that the tris(pyrazolyl)borate ligand coordinates to the aluminum center in kappa(2)-fashion. [HB(3,5-(CF(3))(2)Pz)(3)]ZnEt features the typical kappa(3)-bonded ligand.     

Polyfluorinated Tris(pyrazolyl)borates. Syntheses and Spectroscopic and Structural Characterization of Group 1 and Group 11 Metal Complexes of [HB(3,5-(CF(3))(2)Pz)(3)](-) and [HB(3-(CF(3))Pz)(3)](-)

The fluorinated tris(pyrazolyl)borate ligands [HB(3,5-(CF(3))(2)Pz)(3)](-) and [HB(3-(CF(3))Pz)(3)](-) (where Pz = pyrazolyl) have been synthesized as their sodium salts from the corresponding pyrazoles and NaBH(4) in high yield. These sodium complexes and the related [HB(3,5-(CF(3))(2)Pz)(3)]K(DMAC) were used as ligand transfer agents in the preparation of the copper and silver complexes [HB(3,5-(CF(3))(2)Pz)(3)]Cu(DMAC), [HB(3,5-(CF(3))(2)Pz)(3)]CuPPh(3), [HB(3,5-(CF(3))(2)Pz)(3)]AgPPh(3), and [HB(3-(CF(3))Pz)(3)]AgPPh(3). Metal complexes of the fluorinated [HB(3,5-(CF(3))(2)Pz)(3)](-) ligand have highly electrophilic metal sites relative to their hydrocarbon analogs. This is evident from the formation of stable adducts with neutral oxygen donors such as H(2)O, dimethylacetamide, or thf. Furthermore, the metal compounds derived from fluorinated ligands show fairly long-range coupling between fluorines of the trifluoromethyl groups and the hydrogen, silver, or phosphorus. The solid state structures show that the fluorines are in close proximity to these nuclei, thus suggesting a possible through-space coupling mechanism. Crystal structures of the sodium adducts exhibit significant metal-fluorine interactions. The treatment of [HB(3,5-(CF(3))(2)Pz)(3)]Na(H(2)O) with Et(4)NBr led to [Et(4)N][HB(3,5-(CF(3))(2)Pz)(3)], which contains a well-separated [Et(4)N](+) cation and the [HB(3,5-(CF(3))(2)Pz)(3)](-) anion in the solid state. Crystal data with Mo Kalpha (lambda = 0.710 73 ?) at 193 K: [HB(3,5-(CF(3))(2)Pz)(3)]Na(H(2)O), C(15)H(6)BF(18)N(6)NaO, a = 7.992(2) ?, b = 15.049(2) ?, c = 9.934(2) ?, beta = 101.16(2) degrees, monoclinic, P2(1)/m, Z = 2; [{HB(3-(CF(3))Pz)(3)}Na(thf)](2), C(32)H(30)B(2)F(18)N(12)Na(2)O(2), a = 9.063(3) ?, b = 10.183(2) ?, c = 12.129(2) ?, alpha = 94.61(1) degrees, beta = 101.16(2) degrees, gamma = 95.66(2) degrees, triclinic, &Pmacr;1, Z = 1; [HB(3,5-(CF(3))(2)Pz)(3)]Cu(DMAC), C(19)H(13)BCuF(18)N(7)O, a = 15.124(4) ?, b = 8.833(2) ?, c = 21.637(6) ?, beta = 105.291(14) degrees, monoclinic, P2(1)/n, Z = 4; [HB(3,5-(CF(3))(2)Pz)(3)]CuPPh(3), C(33)H(19)BCuF(18)N(6)P, a = 9.1671(8) ?, b = 14.908(2) ?, c = 26.764(3) ?, beta = 94.891(1) degrees, monoclinic, P2(1)/c, Z = 4; [HB(3,5-(CF(3))(2)Pz)(3)]AgPPh(3).0.5C(6)H(14), C(36)H(26)AgBF(18)N(6)P, a = 13.929(2) ?, b = 16.498(2) ?, c = 18.752(2) ?, beta = 111.439(6) degrees, monoclinic, P2(1)/c, Z = 4; [Et(4)N][HB(3,5-(CF(3))(2)Pz)(3)], C(23)H(24)BF(18)N(7), a = 10.155(2) ?, b = 18.580(4) ?, c = 16.875(5) ?, beta = 99.01(2) degrees, monoclinic, P2(1)/n, Z = 4.     

Synthesis and Characterization of Copper(II), Zinc(II), and Potassium Complexes of a Highly Fluorinated Bis(pyrazolyl)borate Ligand

Highly fluorinated, dihydridobis(3,5-bis(trifluoromethyl)pyrazolyl)borate ligand, [H(2)B(3,5-(CF(3))(2)Pz)(2)](-) has been synthesized and characterized as its potassium salt. The copper(II) and zinc(II) complexes, [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu and [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn, have been prepared by metathesis of [H(2)B(3,5-(CF(3))(2)Pz)(2)]K with Cu(OTf)(2) and Zn(OTf)(2), respectively. All the new metal adducts have been characterized by X-ray diffraction. The potassium salt is polymeric and shows several K.F interactions. The Cu center of [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu adopts a square planar geometry, whereas the Zn atom in [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn displays a tetrahedral coordination. Bis(pyrazolyl)borate ligands in the Zn adduct show a significantly distorted boat conformation. The nature and extent of this distortion is similar to that observed for the methylated analog, [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn. This ligand allows a comparison of electronic effects of bis(pyrazolyl)borate ligands with similar steric properties. Crystallographic data for [H(2)B(3,5-(CF(3))(2)Pz)(2)]K: triclinic, space group P&onemacr;, with a = 8.385(1) ?, b = 10.097(2) ?, c = 10.317(1) ?, alpha = 104.193(9) degrees, beta = 104.366(6) degrees, gamma = 91.733(9) degrees, V = 816.5(3) ?(3), and Z = 2. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu is monoclinic, space group C2/c with a = 25.632(3) ?, b = 9.197(1) ?, c = 17.342(2) ?, beta = 129.292(5) degrees, V = 3164.0(6) ?(3), and Z = 4. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn is triclinic, space group P&onemacr;, with a = 9.104(1) ?, b = 9.278(1) ?, c = 18.700(2) ?, alpha = 83.560(6) degrees, beta = 88.200(10) degrees, gamma = 78.637(9) degrees, V = 1538.8(3) ?(3), and Z = 2. [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn is monoclinic, space group C2/c with a = 8.445(1) ?, b = 14.514(2) ?, c = 19.983(3) ?, beta = 90.831(8) degrees, V = 2449.1(6) ?(3), and Z = 4.     

Synthesis, characterisation and reactivity of germanium(II) amidinate and guanidinate complexes

Reactions of lithium salts of the bulky guanidinate ligands, [ArNC(NR2)NAr](-) (NR2 = N(C6H11)2 (Giso-) and cis-NC5H8Me2-2,6 (Pipiso-); Ar = C6H3Pri2-2,6), with GeCl2.dioxane afforded the heteroleptic germylenes, [(Giso)GeCl] and [(Pipiso)GeCl], the former of which was structurally characterised. The further reactivity of these and the related complexes, [(Piso)GeCl] and [(Priso)GeCl] (Piso- = [ArNC(Bu(t))NAr]-, Priso- = [ArNC(NPri2)NAr]-) has been investigated. Salt elimination reactions have yielded the new monomeric complexes, [(Piso)Ge(NPri2)] and [(Piso)GeFeCp(CO)2], whilst a ligand displacement reaction afforded the heterometallic species, [(Piso)Ge(Cl)(W(CO)5)]. Chloride abstraction from [(Priso)GeCl] with GaCl3 has given the structurally characterised contact ion pair, [(Priso)Ge][GaCl4]. In addition, the inconclusive outcome of a number of attempts to reduce the germanium halide complexes are discussed.     

Aminotroponiminatogermaacid halides with a ge(e)x moiety (e = s, se; x = f, cl)

Fluorination of aminotroponiminate (ATI) ligand-stabilized germylene monochloride [(t-Bu)(2)ATI]GeCl (1) with CsF gave the aminotroponiminatogermylene monofluoride [(t-Bu)(2)ATI]GeF (2). Oxidative addition reaction of compound 2 with elemental sulfur and selenium led to isolation of the corresponding germathioacid fluoride [(t-Bu)(2)ATI]Ge(S)F (3) and germaselenoacid fluoride [(t-Bu)(2)ATI]Ge(Se)F (4), respectively. Similarly, reaction of aminotroponiminatogermylene monochloride [(i-Bu)(2)ATI]GeCl (9) with elemental sulfur and selenium gave the aminotroponiminatogermathioacid chloride [(i-Bu)(2)ATI]Ge(S)Cl (11) and aminotroponiminatogermaselenoacid chloride [(i-Bu)(2)ATI]Ge(Se)Cl (12), respectively. Compound 9 has been prepared through a multistep synthetic route starting from 2-(tosyloxy)tropone 5. All compounds (2-4 and 6-12) were characterized through the multinuclear NMR spectroscopy, and single-crystal X-ray diffraction studies were performed on compounds 2, 4, and 8-12. The germaselenoacid halide complexes 4 and 12 showed doublet (-142.37 ppm) and singlet (-213.13 ppm) resonances in their (77)Se NMR spectra, respectively. Germylene monohalide complexes 2 and 9 have a germanium center in distorted trigonal pyramidal geometry, whereas a distorted tetrahedral geometry is seen around the germanium center in germaacid halide complexes 4, 11, and 12. The length of the Ge═E bond in germathioacid chloride (11) and germaselenoacid halide (4 and 12) complexes is 2.065(1) and 2.194(av) ?, respectively. Theoretical studies (based on the DFT methods) on complexes 4, 11, and 12 reveal the nature of the Ge═E multiple bond in these germaacid halide complexes with computed Wiberg bond indices (WBI) being 1.480, 1.508, and 1.541, respectively.     

Blue phosphors of dinuclear and mononuclear copper(I) and silver(I) complexes of 3,5-bis(trifluoromethyl)pyrazolate and the related bis(pyrazolyl)borate

The synthesis, structure, and photoluminescence properties are described for the three-coordinate mononuclear and dinuclear complexes [H(2)B(3,5-(CF(3))(2)Pz)(2)]M(2,4,6-collidine), M(1)(), and [[3,5-(CF(3))(2)Pz]M(2,4,6-collidine)](2), M(2)(), respectively (M = Cu; Ag). The solids exhibit bright blue phosphorescence, at room temperature for the copper compounds and at 77 K for all compounds. Ag(1)(), Cu(1)(), and Cu(2)() exhibit blue pyrazole-based structured emissions with short phosphorescence lifetimes, 10(1)-10(2) micros, due to an internal heavy-metal effect. Meanwhile, Ag(2)() exhibits curious multiple excitation-dependent emissions.     

Peculiarities of the complexation of copper and silver adducts of a 3,5-bis(trifluoromethyl)pyrazolate ligand with organoiron compounds

Interaction of the copper, {[3,5-(CF(3))(2)Pz]Cu}(3), and silver, {[3,5-(CF(3))(2)Pz]Ag}(3), macrocycles [3,5-(CF(3))(2)Pz = 3,5-bis(trifluoromethyl)pyrazolate] with cyclooctatetraeneiron tricarbonyl, (cot)Fe(CO)(3), was investigated by IR and NMR spectroscopy for the first time. The formation of 1:1 complexes was observed at low temperatures in hexane. The composition of the complexes (1:1) and their thermodynamic characteristics in hexane and dichloromethane were determined. The π-electron system of (cot)Fe(CO)(3) was proven to be the sole site of coordination in solution and in the solid state. However, according to the single-crystal X-ray data, the complex has a different (2:1) composition featuring the sandwich structure. The complexes of ferrocene with copper and silver macrocycles have a columnar structure (X-ray data).     

Supramolecular assemblies of germanium(II) halides with O-, S- and Se-donor macrocycles - the effects of donor atom type upon structure

Reaction of [GeCl(2)(dioxane)] with [18]aneS(6) (1,4,7,10,13,16-hexathiacyclooctadecane) gives the neutral [GeCl(2)([18]aneS(6))] which forms a supramolecular sheet network involving exocyclic coordination, with the macrocycles bridging Ge atoms which are in a pseudo-trigonal bipyramidal environment from two Cl and two S atoms (saw-horse), with one lone pair assumed to occupy the remaining equatorial void. Conversely, using the mixed S/O macrocycles [18]aneS(3)O(3) (1,4,7-trithia-10,13,16-trioxacyclooctadecane) and [15]aneS(2)O(3) (1,4-dithia-7,10,13-trioxacyclopentadecane) (L) leads to the monocationic pentagonal pyramidal [GeCl(L)](+) whose structures show endocyclic Ge coordination, and displacement of one Cl. The Ge-S and Ge-O bond lengths are surprisingly disparate in these two complexes, and in the former the coordinated Cl is axial, while in the latter it occupies the pentagonal plane (with an S atom axial). Cyclic selenoethers form one-dimensional or two-dimensional supramolecular assemblies with Ge(ii) halides, including [GeCl(2)([8]aneSe(2))] ([8]aneSe(2) = 1,5-diselenacyclooctane), [(GeCl(2))(2)([16]aneSe(4))] ([16]aneSe(4) = 1,5,9,13-tetraselenacyclohexadecane), [GeBr(2)([16]aneSe(4))] and [(GeI(2))(2)([16]aneSe(4))]·GeI(4)- these represent the first germanium species with selenoether ligation. Structural studies on each of these show exocyclic GeX(2) coordination, giving networks based upon Se(2)X(2) coordination at Ge(ii) with a distorted pseudo-trigonal bipyramidal environment in which the Ge-based lone pair is assumed to occupy the vacant equatorial vertex. Further weak GeX contacts are also evident in some cases. The weak, secondary GeS/Se and GeX interactions that pervade these systems may be regarded as a further type of supramolecular interaction allowing assembly of new network structures, and the long II contacts evident between the GeI(2) and GeI(4) units in [(GeI(2))(2)([16]aneSe(4))]·GeI(4) probably provide a small thermodynamic contribution leading to co-crystallisation of ordered GeI(4) molecules within the network.     

Low-valent gallium, indium, and tin compounds that contain a highly fluorinated tris(pyrazolyl)borate ligand: syntheses and characterization of

Syntheses and characterization of gallium(I), indium(I), and tin(II) complexes of the [HB(3,5-(CF3)2Pz)3]- ligand (where [HB(3,5-(CF3)2Pz)3]- = hydrotris(3,5-bis(trifluoromethyl)pyrazolyl)borate)) are reported. X-ray crystal structures of [HB(3,5-(CF3)2Pz)3]In and [HB(3,5-(CF3)2Pz)3]Sn(CF3SO3) show monomeric structures in the solid state. The In-N and Sn-N bond distances are longer than the corresponding bond distances of nonfluorinated analogues. NMR data of the gallium(I) adduct [HB(3,5-(CF3)2Pz)3]Ga are very similar to those of the indium(I) analogue suggesting similar solution structures.     

Rhodium pyrazolate complexes as potential CVD precursors

Reaction of 3,5-(CF(3))(2)PzLi with [Rh(μ-Cl)(η(2)-C(2)H(4))(2)](2) or [Rh(μ-Cl)(PMe(3))(2)](2) in Et(2)O gave the dinuclear complexes [Rh(η(2)-C(2)H(4))(2)(μ-3,5-(CF(3))(2)-Pz)](2) (1) and [Rh(2)(μ-Cl)(μ-3,5-(CF(3))(2)-Pz) (PMe(3))(4)] (2) respectively (3,5-(CF(3))(2)Pz = bis-trifluoromethyl pyrazolate). Reaction of PMe(3) with [Rh(COD)(μ-3,5-(CF(3))(2)-Pz)](2) in toluene gave [Rh(3,5-(CF(3))(2)-Pz)(PMe(3))(3)] (3). Reaction of 1 and 3 in toluene (1?:?4) gave moderate yields of the dinuclear complex [Rh(PMe(3))(2)(μ-3,5-(CF(3))(2)-Pz)](2) (4). Reaction of 3,5-(CF(3))(2)PzLi with [Rh(PMe(3))(4)]Cl in Et(2)O gave the ionic complex [Rh(PMe(3))(4)][3,5-(CF(3))(2)-Pz] (5). Two of the complexes, 1 and 3, were studied for use as CVD precursors. Polycrystalline thin films of rhodium (fcc-Rh) and metastable-amorphous films of rhodium phosphide (Rh(2)P) were grown from 1 and 3 respectively at 170 and 130 °C, 0.3 mmHg in a hot wall reactor using Ar as the carrier gas (5 cc min(-1)). Thin films of amorphous rhodium and rhodium phosphide (Rh(2)P) were grown from 1 and 3 at 170 and 130 °C respectively at 0.3 mmHg in a hot wall reactor using H(2) as the carrier gas (7 cc min(-1)).     

Synthesis, structure and DFT study of a pyrazolate stabilized mononuclear Rh(II) complex

Reaction of 3,5-(CF(3))(2)PzLi with anhydrous RhCl(3) in THF gives [Li(THF)](2)Rh(μ-3,5-(CF(3))(2)Pz)(4) (1) as a rare example of a mononuclear, paramagnetic Rh(II) complex (Pz = pyrazolate).     

Copper(I) Nitro Complex with an Anionic [HB(3,5-Me(2)Pz)(3)](-) Ligand: A Synthetic Model for the Copper Nitrite Reductase Active Site

The new copper(I) nitro complex [(Ph(3)P)(2)N][Cu(HB(3,5-Me(2)Pz)(3))(NO(2))] (2), containing the anionic hydrotris(3,5-dimethylpyrazolyl)borate ligand, was synthesized, and its structural features were probed using X-ray crystallography. Complex 2 was found to cocrystallize with a water molecule, and X-ray crystallographic analysis showed that the resulting molecule had the structure [(Ph(3)P)(2)N][Cu(HB(3,5-Me(2)Pz)(3))(NO(2))]·H(2)O (3), containing a water hydrogen bonded to an oxygen of the nitrite moiety. This complex represents the first example in the solid state of an analogue of the nitrous acid intermediate (CuNO(2)H). A comparison of the nitrite reduction reactivity of the electron-rich ligand containing the CuNO(2) complex 2 with that of the known neutral ligand containing the CuNO(2) complex [Cu(HC(3,5-Me(2)Pz)(3))(NO(2))] (1) shows that reactivity is significantly influenced by the electron density around the copper and nitrite centers. The detailed mechanisms of nitrite reduction reactions of 1 and 2 with acetic acid were explored by using density functional theory calculations. Overall, the results of this effort show that synthetic models, based on neutral HC(3,5-Me(2)Pz)(3) and anionic [HB(3,5-Me(2)Pz)(3)](-) ligands, mimic the electronic influence of (His)(3) ligands in the environment of the type II copper center of copper nitrite reductases (Cu-NIRs).     

Brightly phosphorescent trinuclear copper(I) complexes of pyrazolates: substituent effects on the supramolecular structure and photophysics

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.     

Copper and silver complexes containing organic azide ligands: syntheses, structures, and theoretical investigation of [HB(3,5-(CF3)2Pz)3]CuNNN(1-Ad) and [HB(3,5-(CF3)2Pz)3]AgN(1-Ad)NN (where Pz = pyrazolyl and 1-Ad = 1-adamantyl)

Treatment of [HB(3,5-(CF3)2Pz)3]Na(THF) with CF3SO3Cu followed by 1-azidoadamantane affords [HB(3,5-(CF3)2Pz)3]CuNNN(1-Ad) in 65% yield. The solid state structure shows that the copper atom is coordinated to the terminal nitrogen atom (NT) of the azidoadamantane ligand. The related silver(I) adduct can be prepared in 80% yield by the treatment of [HB(3,5-(CF3)2Pz)3]Ag(THF) with 1-azidoadamantane. However, [HB(3,5-(CF3)2Pz)3]AgN(1-Ad)NN shows a different bonding mode where the silver atom coordinates to the alkylated nitrogen atom (NA) of the azidoadamantane ligand. Asymmetric stretching bands of the azido group for copper and silver adducts appear at 2143 and 2120 cm-1, respectively. Theoretical investigation shows that steric effects do not play a dominant role in determining the bonding mode of the azide ligand in these two metal complexes. Although the copper(I) ion affinity for the two coordinating sites NT and NA is nearly identical, copper-azide back-bonding interactions favor the copper-NT mode of bonding over the copper-NA mode. Silver (a very poor back-bonding metal) prefers the NA site for coordination. The NA site has a significantly higher proton affinity and slightly higher sodium ion affinity. Important structural parameters for [HB(3,5-(CF3)2Pz)3]CuNNN(1-Ad) and [HB(3,5-(CF3)2Pz)3]AgN(1-Ad)NN are as follows: Cu-NT 1.861(3) A, NT-N 1.136(4) A, N-NA 1.219(4) A, NT-N-NA 173.1(3) degrees; Ag-NA 2.220(5) A, NT-N 1.143(12) A, N-NA 1.227(10) A, NT-N-NA 176.8(12) degrees. Overall, the azidoadamantane ligand does not undergo any significant changes upon coordination to Cu(I) or Ag(I) ions.     

Organometallic chemistry of fluorinated allenes

Reaction of 1,1-difluoroallene and tetrafluoroallene with a series of transition metal complex fragments yields the mononuclear allene complexes [CpMn(CO)(2)(allene)] (1), [(CO)(4)Fe(allene)] (2), [(Ph(3)P)(2)Pt(C(3)H(2)F(2))] (4), [Ir(PPh(3))(2)(C(3)H(2)F(2))(2)Cl] (5), and the dinuclear complexes [mu-eta(1)-eta(3)-C(3)H(2)F(2))Fe(2)(CO)(7)] (3), [Ir(PPh(3))(C(3)H(2)F(2))(2)Cl](2) (6), and [mu-eta(2)-eta(2)-C(3)H(2)F(2))(CpMo(CO)(2))(2)] (9), respectively. In attempts to synthesize cationic complexes of fluorinated allenes [CpFe(CO)(2)(C(CF(3))=CH(2))] (7a), [CpFe(CO)(2)(C(CF(3))=CF(2))] (7b) and [mu-I-(CpFe(CO)(2))(2)][B(C(6)H(3)-3,5-(CF(3))(2))(4)] were isolated. The spectroscopic and structural data of these complexes revealed that the 1,1-difluoroallene ligand is coordinated exclusively with the double bond containing the hydrogen-substituted carbon atom. 1,1-Difluoroallene and tetrafluoroallene proved to be powerful pi acceptor ligands.     

Synthesis, structures and photophysical properties of luminescent copper(I) and platinum(II) complexes with a flexible naphthyridine-phosphine ligand

Condensation of Ph(2)PH and paraformaldehyde with 2-amino-7-methyl-1,8-naphthyridine gave the new flexible tridentate ligand 2-[N-(diphenylphosphino)methyl]amino-7-methyl-1,8-naphthyridine (L). Reaction of L with [Cu(CH(3)CN)(4)]BF(4) and/or different ancillary ligands in dichloromethane afforded N,P chelating or bridging luminescent complexes [(L)(2)Cu(2)](BF(4))(2), [(micro-L)(2)Cu(2)(PPh(3))(2)](BF(4))(2) and [(L)Cu(CNN)]BF(4) (CNN = 6-phenyl-2,2'-bipyridine), respectively. Complexes [(L)(2)Pt]Cl(2), [(L)(2)Pt](ClO(4))(2) and [(L)Pt(CNC)]Cl (CNC = 2,6-biphenylpyridine) were obtained from the reactions of Pt(SMe(2))(2)Cl(2) or (CNC)Pt(DMSO)Cl with L. The crystal structures and photophysical properties of the complexes are presented.     

Carbophosphazene-supported ligand systems containing pyrazole/guanidine coordinating groups

Carbophosphazene-based coordination ligands [{NC(NMe(2))}(2){NP(3,5-Me(2)Pz)(2)}] (1), [{NC(NEt)(2)}{NC(3,5-Me(2)Pz)}{NP(3,5-Me(2)Pz)(2)}] (2), [NC(3,5-Me(2)Pz)](2)[NP(3,5-Me(2)Pz)(2)] (3), [{NCCl}(2){NP(NC(NMe(2))(2))(2)}] (4), and [{NC(p-OC(5)H(4)N)}(2){NP(NC(NMe(2))(2))(2)}] (5) were synthesized and structurally characterized. In these compounds, the six-membered C(2)N(3)P ring is perfectly planar. The reaction of 1 with CuCl(2) afforded [{NC(NMe(2))}(2){NHP(O)(3,5-Me(2)Pz)}·{Cu(3,5-Me(2)PzH)(2)(Cl)}][Cl] (6). The ligand binds to Cu(II) utilizing the geminal [P(O)(3,5-Me(2)Pz)] coordinating unit. Similarly, the reaction of 2 with PdCl(2) afforded, after a metal-assisted P-N hydrolysis, [{NC(NEt)(2)}{NC(3,5-Me(2)Pz)}{NP(O)(3,5-Me(2)Pz)}·{Pd(3,5-Me(2)PzH)(Cl)}] (7). In the latter, the [P(O)(3,5-Me(2)Pz)] unit does not coordinate; in this instance, the Pd(II) is bound by a ring nitrogen atom and a carbon-tethered pyrazolyl nitrogen atom. The reaction of 3 with PdCl(2) also results in P-N bond hydrolysis affording [{NC(3,5-Me(2)Pz)(2)}{NP(O)(3,5-Me(2)Pz)}{Pd(Cl)}] (8). In contrast to 7, however, in 8, the Pd(II) elicits a nongeminal η(3) coordination from the ligand involving two carbon-tethered pyrazolyl groups and a ring nitrogen atom. Metalated products could not be isolated in the reaction of 3 with K(2)PtCl(4). Instead, a P-O-P bridged carbodiphosphazane dimer, [{NC(3,5-Me(2)Pz)NHC(3,5-Me(2)Pz)}{NP(O)}](2) (9), was isolated as the major product. Finally, the reaction of 5 with PdCl(2) resulted in [{NC(OC(5)H(4)N)}(2){NP(NC(NMe(2))(2))(2)}·{PdCl(2)}] (10). In the latter, the exocyclic P-N bonds are quite robust and are involved in binding to the metal ion. Compounds 6-10 have been characterized by a variety of techniques including X-ray crystallography. In all of the compounds, the bond parameters of the inorganic heterocyclic rings are affected by metalation.     

Aqueous reactions of U(VI) at high chloride concentrations: syntheses and structures of new uranyl chloride polymers

The reactions of UO(3) with acidic aqueous chloride solutions resulted in the formation of two new polymeric U(VI) compounds. Single crystals of Cs(2)[(UO(2))(3)Cl(2)(IO(3))(OH)O(2)].2H(2)O (1) were formed under hydrothermal conditions with HIO(3) and CsCl, and Li(H(2)O)(2)[(UO(2))(2)Cl(3)(O)(H(2)O)] (2) was obtained from acidic LiCl solutions under ambient temperature and pressure. Both compounds contain pentagonal bipyramidal coordination of the uranyl dication, UO(2)(2+). The structure of 1 consists of infinite [(UO(2))(3)Cl(2)(IO(3))(mu(3)-OH)(mu(3)-O)(2)](2-) ribbons that run down the b axis that are formed from edge-sharing pentagonal bipyramidal [UO(6)Cl] and [UO(5)Cl(2)] units. The Cs(+) cations separate the chains from one another and form long ionic contacts with terminal oxygen atoms from iodate ligands, uranyl oxygen atoms, water molecules, and chloride anions. In 2, edge-sharing [UO(3)Cl(4)] and [UO(5)Cl(2)] units build up tetranuclear [(UO(2))(4)(mu-Cl)(6)(mu(3)-O)(2)(H(2)O)(2)](2-) anions that are bridged by chloride to form one-dimensional chains. These chains are connected in a complex network of hydrogen bonds and interactions of uranyl oxygen atoms with Li(+) cations. Crystal data: 1, orthorhombic, space group Pnma, a = 8.2762(4) A, b = 12.4809(6) A, c = 17.1297(8) A, Z = 4; 2, triclinic, space group P1, a = 8.110(1) A, b = 8.621(1) A, c = 8.740(1) A, Z = 2.