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1.
Reactions of [(η 6-arene)RuCl 2] 2 (1) (η 6-arene= p-cymene (1a), 1,3,5-Me 3C 6H 3 (1b), 1,2,3-Me 3C 6H 3 (1c) 1,2,3,4-Me 4C 6H 2(1d), 1,2,3,5-Me 4C 6H 2 (1e) and C 6Me 6 (1f)) or [Cp*MCl 2] 2 (M=Rh (2), Ir (3); Cp*=C 5Me 5) with 4-isocyanoazobenzene (RNC) and 4,4′-diisocyanoazobenzene (CN–R–NC) gave mononuclear and dinuclear complexes, [(η 6-arene)Ru(CNC 6H 4N=NC 6H 5)Cl 2] (4a–f), [Cp*M(CNC 6H 4N=NC 6H 5)Cl 2] (5: M=Rh; 6: M=Ir) , [{(η 6-arene)RuCl 2} 2{μ-CNC 6H 4N=NC 6H 4NC}] (8a–f) and [(Cp*MCl 2) 2(μ-CNC 6H 4N=NC 6H 4NC)}] (9: M=Rh; 10: M=Ir) , respectively. It was confirmed by X-ray analyses of 4a and 5 that these complexes have trans-forms for the ---N=N--- moieties. Reaction of [Cp*Rh(dppf)(MeCN)](PF 6) 2 (dppf=1,1′-bis (diphenylphosphino)ferrocene) with 4-isocyanoazobenzene gave [Cp*Rh(dppf)(CNC 6H 4N=NC 6H 5)](PF 6) 2 (7), confirmed by X-ray analysis. Complex 8b reacted with Ag(CF 3SO 3), giving a rectangular tetranuclear complex 11b, [{(η 6-1,3,5-Me 3C 6H 3)Ru(μ-Cl} 4(μ-CNC 6H 4N=NC 6H 4NC) 2](CF 3SO 3) 4 bridged by four Cl atoms and two μ-diisocyanoazobenzene ligands. Photochemical reactions of the ruthenium complexes (4 and 8) led to the decomposition of the complexes, whereas those of 5, 7, 9 and 10 underwent a trans-to- cis isomerization. In the electrochemical reactions the reductive waves about −1.50 V for 4 and −1.44 V for 8 are due to the reduction of azo group, [---N=N---]→[---N=N---] 2−. The irreversible oxidative waves at ca. 0.87 V for the 4 and at ca. 0.85 V for 8 came from the oxidation of Ru(II)→Ru(III). 相似文献
2.
Reaction of [U(Tp Me2) 2(NR 2)] (R = Ph, SiMe 3) with protic substrates such as 2,4,6-trimethylphenol (HOC 6H 2-2,4,6-Me 3), 3,5-dimethylpyrazole (Hdmpz), 2-mercaptopyridine (HSC 5H 4N) and phenylacetylene (HCCPh) afforded the corresponding [U(Tp Me2) 2(OAr)] (Ar = C 6H 2-2,4,6-Me 3) (1), [U(Tp Me2) 2(dmpz)] (2), [U(Tp Me2) 2(η 2-SC 5H 4N)] (3), and [U(Tp Me2) 2(CCPh)] (4) compounds. Reaction of [U(Tp Me2) 2(NR 2)] with Me 3SnCl or Me 3SiBr gave [U(Tp Me2) 2Cl] (5) and [U(Tp Me2) 2Br] (6), respectively, in high yield. The amido precursors failed to react with cyclopentadiene, but metathesis of [U(Tp Me2) 2I] with NaCp yielded [U(κ 3-Tp Me2)(κ 2-Tp Me2)(η 5-Cp)] (7). Thermolysis of 7 resulted in oxidation of the metal centre and redistribution of the ligands, giving [UCp 3(dmpz)] (8), pyrazabole (9) and [U(Tp Me2)(dmpz) 3] (10). The complexes have been fully characterized by spectroscopic methods and the structures of 1, 2, and 5 were confirmed by X-ray crystallographic studies. In the solid state the complexes exhibit distorted pentagonal bipyramidal geometries. 相似文献
3.
The new diphenolato complexes [{Mo(NO){HB(dmpz) 3}Cl} 2Q] where dmpz = 3,5-dimethylpyrazolyl and Q = OC 6H 4(C 6H 4O ( n = 1 or 2), OC 6H 4CR=CRC 6H 4O (R = H or Et), and OC 6H 4CH=CHC 6H 4CH=CHC 6H 4O have been prepared and their electrochemical properties (cyclic and differential pulse voltammetry) compared with previously reported analogues where Q = OC 6H 4O, OC 6H 4EC 6H 4O (E = SO 2, CO and S), OC 6H 4 (CO)C 6H 4 C 6H 4(CO)C 6H 4O and 1,5- and 2,7-O 2C 10H 6. The electrochemical interaction between the redox centres in the new complexes is very weak, in contrast to that in the 1,4-benzenediolato and naphthalendiolato species. The EPR spectra of the reduced mixed-valence species [{Mo(NO){HB(dmpz) 3}Cl} 2Q] − where Q = 1,3- and 1,4-OC 6H 4O and OC 6H 4SC 6H 4O shows that they are valence-trapped at room temperature, whereas those of the dianions [{Mo(NO){HB(dmpz) 3}Cl} 2Q] 2− where Q = 1,4-OC 6H 4O, OC 6H 4EC 6H 4O (E = CO or S) and OC 6H 4CH=CHC 6H 4CH=CHC 6H 4O shows that the unpaired spins on each molybdenum centre are strongly correlated ( J, the spin exchange integral A Mo, the metal-hyperfine coupling constant). The electrochemical properties and the comproportionation constants for the reaction [{Mo(NO){HB(dmpz) 3} Cl} 2Q] + [{Mo(NO){HB(dmpz) 3}Cl}O] 2] 2−2[{Mo(NO) {HB(dmpz) 3}Cl} 2Q] − where Q = diphenolato bridge, are compared with related compounds containing benzenediamido and dianilido bridges. 相似文献
4.
Recent results (post-1990) on the synthesis and structures of bis(trimethylsilyl)methyls M(CHR 2) m (R = SiMe 3) of metals and metalloids M are described, including those of the crystalline lipophilic [Na(μ-CHR 2)] ∞, [Rb(μ-CHR 2)(PMDETA)] 2, K 4(CHR 2) 4(PMDETA) 2, [Mg(CHR 2)(μ-CHR 2)] ∞, P(CHR 2) 2 (gaseous) and P 2(CHR 2) 4, [Yb(CHR 2) 2(OEt 2) 2] and [{Yb(CR 3)(μ-OEt)(OEt 2)} 2]; earlier information on other M(CHR 2) m complexes and some of their adducts is tabulated. Treatment of M(CHR 2) (M = Li or K) with four different nitriles gave the X-ray-characterized azaallyls or β-diketinimates
,
and
(LL′ = N(R)C( tBu)CHR, L′L′ = N(R)C(Ph)C(H)C(Ph)NR, LL″ = N(R)C(Ph)NC(H)C(Ph)CHR, R = SiMe 3 and Ar = C 6H 3Me 2-2,5). The two lithium reagents were convenient sources of other metal azaallyls or β-diketinimates, including those of K, Co(II), Zr(IV), Sn(IV), Yb(II), Hf(IV) and U(VI)/U(III). Complexes having one or more of the bulky ligands [LL′] −, [L′L′] −, [LL] −, [LL″] −, [L″L] −, [LL] − and [{N(R)C( tBu)CH} 2C 6H 4-2] 2− are described and characterized (LL = N(H)C(Ph)C(H)C(Ph)NH, L″L = N(R)C( tBu)C(H)C(Ph)NR, LL = N(R)C( tBu)CHPh). Among the features of interest are (i) the contrasting tetrahedral or square-planar geometry for
and
, respectively, and (ii) olefin-polymerization catalytic activity of some of the zirconium(IV) chlorides. 相似文献
5.
Treatment of the diaminobenzene [C 6H 4{CH 2NMe 2} 2-1,3] (NCN-H, 1) with one or two equivalents of cis-PtCl 2(DMSO) 2 leads to exclusive formation of the doubly cycloplatinated species [C 6H 4{CH 2NMe 2} 2-1,5-{PtCl(DMSO)} 2-2,4] (3), which upon addition of triphenylphosphine yields the bisphosphine adduct [C 6H 4{CH 2NMe 2} 2-1,5-{PtCl(PPh 3)} 2-2,4] (4). The X-ray molecular structure of 4 revealed the presence of highly distorted square planar Pt(II) centers which is caused by close proximity of the two phosphine donor ligands. Complexes of type 3 can be regarded as suitable starting materials for the directional build-up of larger macromolecular structures. 相似文献
6.
The reaction of the anionic mononuclear rhodium complex [Rh(C 6F 5) 3Cl(Hpz)] t- (Hpz = pyrazole, C 3H 4N 2) with methoxo or acetylacetonate complexes of Rh or Ir led to the heterodinuclear anionic compounds [(C 6F 5) 3Rh(μ-Cl)(μ-pz)M(L 2)] [M = Rh, L 2 = cyclo-octa-1,5-diene, COD (1), tetrafluorobenzobarrelene, TFB (2) or (CO) 2 (4); M = Ir, L 2 = COD (3)]. The complex [Rh(C 6F 5) 3(Hbim)] − (5) has been prepared by treating [Rh(C 6F 5) 3(acac)] − with H 2bim (acac = acetylacetonate; H 2bim = 2,2′-biimidazole). Complex 5 also reacts with Rh or Ir methoxo, or with Pd acetylacetonate, complexes affording the heterodinuclear complexes [(C 6F 5) 3Rh(μ-bim)M(L 2)] − [M = Rh, L 2 = COD (6) or TFB (7); M = Ir, L 2 = COD (8); M = Pd, L 2 = η 3-C 3H 5 (9)]. With [Rh(acac)(CO) 2], complex 5 yields the tetranuclear complex [{(C 6F 5) 3Rh(μ-bim)Rh(CO) 2} 2] 2−. Homodinuclear Rh III derivatives [{Rh(C 6F 5) 3} 2(μ-L) 2] ·- [L 2 = OH, pz (11); OH, S tBu (12); OH, SPh (13); bim (14)] have been obtained by substitution of one or both hydroxo groups of the dianion [{Rh(C 6F 5) 3(μ-OH)} 2] 2− by the corresponding ligands. The reaction of [Rh(C 6F 5) 3(Et 2O) x] with [PdX 2(COD)] produces neutral heterodinuclear compounds [(C 6F 5) 3Rh(μ-X) 2Pd(COD)] [X = Cl (15); Br (16)]. The anionic complexes 1–14 have been isolated as the benzyltriphenylphosphonium (PBzPh 3+) salts. 相似文献
7.
The interaction of [(η 5-C 5H 4Bu t) 2YbCl · LiCl] with one equivalent of Li[(CH 2) (CH 2)PPh 2] in tetrahydrofuran gave [Ph 2PMe 2][(η 5-C 5H 4Bu t) 2Li] (1) and [(η 5-C 5H 4Bu t) 2Yb(Cl)CH 2P(Me)Ph 2] (2) in 10% and 30% yields, respectively. 1 could also be prepared in 70% yield from the reaction of [Ph 2PMe 2][CF 3SO 3] with two equivalents of (C 5H 4Bu t)Li. Both compounds have been fully characterized by analytical, spectroscopic and X-ray diffraction methods. The solid state structure of 1 reveals a sandwich structure for the [(η 5-C 5H 4Bu t) 2Li] − anion. 相似文献
8.
The coordinatively unsaturated uranium(IV) complex U[N(C 6H 5) 2] 4 has been prepared via the stoichiometric reaction of diphenylamine with [(Me 3Si) 2N] 2
H 2. U[N(C 6H 5) 2] 4 coordinates Lewis bases such as Et 2O, THF, pyridine or (EtO) 3PO, based on electronic absorption spectroscopy and 1H NMR studies. Exchange between U[N(C 6H 5) 2] 4 and U[N(C 6H 5) 2] 4(L), where L is THF or pyridine, is rapid on the NMR time-scale between 307 and 323 K. Measurement of equilibrium constants for L = THF provides Δ H and Δ S values of −60 kJ mol −1 and −1.8 × 10 2 J K −1 mol −1, respectively. U[N(C 6H 5) 2] 4 coordinates and binds (EtO) 3PO much more tightly ( Keq = & > 10 4 M −1) than THF or pyridine with the exchange rate between U[N(C 6H 5) 2] 4 and U[N(C 6H 5) 2] 4[OP(OEt) 3] being close to the NMR time-scale. 相似文献
9.
Neutral salicylaldiminato Ni(II) complexes bearing a single N-heterocyclic carbene (NHC) ligand [3,5- tBu 2-2-(O)C 6H 2CHNAr]Ni(C{RNCHCHN iPr})Ph [Ar = 2,6- iPr 2C 6H 3, R = Bn (1); Ar = 2,6- iPr 2C 6H 3, R = iPr (2)], have been synthesized via a one-pot procedure in high yield. The X-ray structure analysis reveals that both of 1 and 2 adopt distorted square-planar coordination geometry and NHC carbon (C carbene) is trans to the ketimine nitrogen. Preliminary study indicates that complex 1 is inert toward the insertion of ethylene, however, it can catalyze the dimerization of ethylene in the presence of modified methylaluminoxane (MMAO) with a moderate activity of 3.05 × 10 4 g(mol Ni) −1 h −1 atm −1 in a highly selective fashion. 相似文献
10.
Reactions of [C 6F 5Xe] + [AsF 6] − in acetonitrile with halide anions X − show different results depending on X. If X = I, Br or Cl, then C 6F 5X is obtained. If X = F, then C 6F 5H and C 6F 5---C 6F 5 are produced, and if X = HF 2, then C 6F 6, C 6F 5H and C 6F 5---C 6F 5 are formed. 相似文献
11.
The collisional quenching of electronically excited germanium atoms, Ge[4p 2( 1S 0)], 2.029 eV above the 4p 2( 3P 0) ground state, has been investigated by time-resolved atomic resonance absorption spectroscopy in the ultraviolet at λ = 274.04 nm [4d( 1P 10) ← 4p 2( 1S 0)]. In contrast to previous investigations using the ‘single-shot mode’ at high energy, Ge( 1S 0) has been generated by the repetitive pulsed irradiation of Ge(CH 3) 4 in the presence of excess helium gas and added gases in a slow flow system, kinetically equivalent to a static system. This technique was originally developed for the study of Ge[4p 2( 1D 2)] which had eluded direct quantitative kinetic study until recently. Absolute second-order rate constants obtained using signal averaging techniques from data capture of total digitised atomic decay profiles are reported for the removal of Ge( 1S 0) with the following gases ( kR in cm 3 molecule −1 s −1, 300 K): Xe, 7.1 ± 0.4 × 10 −13; N 2, 4.7 ± 0.6 × 10 −12; O 2, 3.6 ± 0.9 × 10 −11; NO, 1.5 ± 0.3 × 10 −11; CO, 3.4 ± 0.5 × 10 −12; N 2O, 4.5 ± 0.5 × 10 −12; CO 2, 1.1 ± 0.3 × 10 −11; CH 4, 1.7 ± 0.2 × 10 −11; CF 4, 4.8 ± 0.3 × 10 −12; SF 6, 9.5 ± 1.0 × 10 −13; C 2H 4, 3.3 ± 0.1 × 10 −10; C 2H 2, 2.9 ± 0.2 × 10 −10; Ge(CH 3) 4, 5.4 ± 0.2 × 10 −11. The results are compared with previous data for Ge( 1S 0) derived in the single-shot mode where there is general agreement though with some exceptions which are discussed. The present data are also compared with analogous quenching rate data for the collisional removal of the lower lying Ge[4p 2( 1D 2)] state (0.883 eV), also characterized by signal averaging methods similar to that described here. 相似文献
12.
Liquid crystalline 4-XC 6H 4N=NC 6H 4X-4′ [X = C 4H 9 (1a), C 1OH 21 (1b), OC 4H 9 (1c), OC 8H 17(1d)] can be easily prepared in high yields from the corresponding anilines. In order to study the influence of metals on the thermal properties of these materials, we have obtained adducts [AuCl 3(4-C 4H 9OC 6H 4N=NC 6H 4OC 4H 9-4′)] (2) and [Ag(OC1O 3)L 2] [L = 4-XC 6H 4N=NC 6H 4X-4′; X = OC 4H, (3a), OC 8H 17 (3b)]. The silver adducts show themotropic behaviour. Mercuriation of dialkylazobenzenes 1a-b takes place with [Hg(OAc) 2] and LiCl to give [Hg(R)Cl] [R = C 6H 3(N=NC 6H 4X-4′)-2, X-5; X = C 4H 9 (bpap) (4a), C 10H 21 (dpap) (4b)] while dialkoxyazobenzenes 1c–d require [Hg (OOCCF 3) 2] to obtain [Hg(R)Cl] [R = C 6H 3(N---NC 6H 4X-4′)-2, X-5; X = OC 4H 9 (bxpap) (4c), OC 8H 17 (4d)]. 4a-c react with NaI to give [HgR 2] [R= bpap (5a), dpap (5b), bxpap (5c), oxpap (5d)l. Both chloroaryl-, 4a and 4c, and diaryl-mercurials, 5a and 5c, act readily as transmetailating agents towards [Me 4N] [AuCl 4] in the presence of [Me 4N]Cl to give [Au(η 2-R)Cl 2] [R = bpap (6a), bxpap (6b)]. After reaction of [AuCl 3(tht)] (tht = tetrahydrothiophene) with [Me 4N]Cl and 4b (1:2:1), [Me 4N][Au(dpap)Cl 3] (7) can be isolated. C---H activati bxpap (8b)]. None of the complexes 4–8 shows mesomorphic behaviour. 相似文献
13.
The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen 2) 2V 4O 12]·5H 2O (1) and [Ni(phen) 3] 2[V 4O 12]·17.5H 2O (2). Crystal data: C 48H 52Cd 2N 8O 22V 4 (1), triclinic.
a=10.3366(10), b=11.320(3), c=13.268(3) Å, =103.888(17)°, β=92.256(15)°, γ=107.444(14)°, Z=1; C 72H 131N 12Ni 2O 29.5V 4 (2), triclinic.
a=12.305(3), b=13.172(6), c=15.133(4), =79.05(3)°, β=76.09(2)°, γ=74.66(3)°, Z=1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59° <θ<26.02° and 2.01°<θ<25.01° using the ω-scan technique, respectively. The structure of 1 consists of a [V 4O 12] 4− cluster covalently attached to two {Cd(phen) 2} 2+ fragments, in which the [V 4O 12] 4− cluster adopts a chair-like configuration. In the structure of 2, the [V 4O 12] 4− cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the [V 4O 12] 4− unit and crystallization water molecules. 相似文献
14.
When heated under reflux in CH 2Cl 2 solution with [Os(CO) 3Cl 2] 2, two nido-[B 9H 12] − units edge-fuse to form anti-[B 18H 21] −. 相似文献
15.
The reaction of the labelled carborane ligand [3-Et-7,8-Ph 2-7,8- nido-C 2B 9H 8] 2− with a source of {Pt(PMe 2Ph) 2} 2+ affords non-isomerised 1,2-Ph 2-3,3-(PMe 2Ph) 2-6-Et-3,1,2- closo-PtC 2B 9H 8 (1). The analogous reaction between [3-F-7,8-Ph 2-7,8- nido-C 2B 9H 8] 2− and {Pt(PMe 2Ph) 2} 2+ yields 1,8-Ph 2-2,2-(PMe 2Ph) 2-4-F-2,1,8- closo-PtC 2B 9H 8 (3). Compound 1 has a heavily slipped structure ( Δ 0.72 Å), which to some degree obviates the need for C atom isomerisation. However, that it is a kinetic product of the reaction is evident from the fact that it reverts to isomerised 1,8-Ph 2-2,2-(PMe 2Ph) 2-4-Et-2,1,8- closo-PtC 2B 9H 8 (2) slowly at room temperature but more rapidly with gentle warming. The heteroatom and labelled-B atom positions in the isomerised compounds 2 and 3 may be explained most simply by the rotation of a CB 2 face of an intermediate based on the structure of 1. Compounds 1–3 were characterised by a combination of spectroscopic and crystallographic techniques. 相似文献
16.
The reaction of [AuCl(PPh 3)] with Pb(SR) 2(R = C 2H 5, C 6H 5, CH 2C 6H 5, C 6F 5, C 6H 2Me 3-2,4,6, Pr i and Bu t) provides a clean method to obtain complexes of the type [Au(SR)(PPh 3)] in good yields. The new compounds have been characterized by IR, 1H, 31P, 19F and 31C NMR. A study by FAB mass spectrometry indicates that an ion-molecule aggregation process takes place. 相似文献
17.
Reaction of [Cp *TiF 3] (Cp * = (ν 5-C 5Me 5)) with Me 3SiOSO 2- p-C 6H 4CH 3, Me 3SiOPOPh 2 and 1,2-(Me 3SiOCO) 2C 6H 4 yields the dinuclear complexes [{Cp *TiF(μ-F)(μ-OSO 2- p-C 6H 4CH 4)} 2] (1), [{Cp *TiF(μ-F)(μ-OPOPh 2)} 2] (2) and [{Cp *TiF(μ-F)(μ-OCO- o-C 6H 4CO 2SiMe 3)} 2] (3). The molecular structures of 1 and 2 have been determined by single-crystal X-ray analysis. In complexes 1-3, the two titanium atoms are connected by bridging fluorine atoms as well as bridging sulfonate, phosphinate and carboxylate groups respectively. Each titanium atom is also bonded to a terminal fluorine atom. Reaction of [Cp 2*ZrF 2] with 1,2-(Me 3SiOCO) 2C 6H 4 leads to the mononuclear pentacoordinate 18-electron species [Cp 2*ZrF(μ-OCO- o-C 6H 4CO 2SiMe 3)] (4) and its structure was determined by X-ray crystallographic methods. 相似文献
18.
The synthesis, crystal structure and magnetic measurements of three new polynuclear tetracarboxylato-bridged copper(II) complexes, i.e. {[Cu 4(phen) 2(μ-O 2CC 2H 5) 8] · (H 2O)} n (1), [Cu 2(μ-O 2CC 6H 4OH) 4(C 7H 7NO) 2] · 6H 2O (2) and [Cu 2(μ-O 2CCH 3) 4(C 7H 7NO) 2] (3) (phen = 1,10-phenanthroline, O 2CC 6H 4OH = 3-hydroxy benzoate, C 7H 7NO = 4-acetylpyridine) are reported. All compounds consist of dinuclear units, in which two Cu(II) ions are bridged by four syn, syn-η 1:η 1:μ carboxylates, showing a paddle-wheel cage type with a square-pyramidal geometry, arranged in different ways. The structure of compound 1 consists of an one-dimensional structure generated by an alternating classical dinuclear paddle-wheel unit and an unusual dinuclear Cu 2(μ-OCOC 2H 5) 2(μ-O 2CC 2H 5) 2(phen) 2unit, which are connected to each other via a syn, anti-triatomic propionato bridge in an axial-equatorial configuration. The adjacent chains are connected to generate a 2D structure through the face-to-face π–π interaction between phen rings. Structures of compounds 2 and 3 both consist of a symmetric dinuclear Cu(II) carboxylate paddle-wheel core and pyridyl nitrogen atoms of 4-acetylpyridine ligand at the apical position, and just differ in the substituents of the equatorial ligands. The magnetic properties have been measured and correlated with the molecular structures. It is found that in the two classical paddle-wheel compounds the Cu(II) ions are strongly antiferromagnetically coupled with J = −278.5 and −287.0 cm−1 for complexes 2 and 3, respectively. In compound 1 the magnetic susceptibility could be fitted with two different, independent Cu(II) units, one strongly coupled and one weakly coupled; the paddle-wheel dinuclear unit has the strongest antiferromagetic coupling with a value for J of −299.5 cm−1, whereas the Cu(II) ions in the propionato-bridged dinuclear unit of 1 display a very weak antiferromagnetic coupling with a value for J = −0.75 cm−1, due to the orthogonality of the magnetic orbitals. Also the exchange within the chain is therefore very weak. The magneto-structural correlations for complexes 1, 2, and 3 are discussed on the basis of the structural parameters and magnetic data for the complexes. 相似文献
19.
The reactions of RNHSi(Me) 2Cl (1, R= t-Bu; 2, R=2,6-(Me 2CH) 2C 6H 3) with the carborane ligands, nido-1-Na(C 4H 8O)-2,3-(SiMe 3) 2-2,3-C 2B 4H 5 (3) and Li[ closo-1-R′-1,2-C 2B 10H 10] (4), produced two kinds of neutral ligand precursors, nido-5-[Si(Me) 2N(H)R]-2,3-(SiMe 3) 2-2,3-C 2B 4H 5, (5, R= t-Bu) and closo-1-R′-2-[Si(Me) 2N(H)R]-1,2-C 2B 10H 10 (6, R= t-Bu, R′=Ph; 7, R=2,6-(Me 2CH) 2C 6H 3, R′=H), in 85, 92, and 95% yields, respectively. Treatment of closo-2-[Si(Me) 2NH(2,6-(Me 2CH) 2C 6H 3)]-1,2-C 2B 10H 11 (7) with three equivalents of freshly cut sodium metal in the presence of naphthalene produced the corresponding cage-opened sodium salt of the “carbons apart” carborane trianion, [ nido-3-{Si(Me) 2N(2,6-(Me 2CH) 2C 6H 3)}-1,3-C 2B 10H 11] 3− (8) in almost quantitative yield. The reaction of the trianion, 8, with anhydrous MCl 4 (M=Ti and Zr) in 1:1 molar ratio in dry tetrahydrofuran (THF) at −78 °C, resulted in the formation of the corresponding half-sandwich neutral d 0-metallacarborane, closo-1-M[(Cl)(THF) n]-2-[1′-η 1σ-N(2,6-(Me 2CH) 2C 6H 3)(Me) 2Si]-2,4-η 6-C 2B 10H 11 (M=Ti (9), n=0; M=Zr (10), n=1) in 47 and 36% yields, respectively. All compounds were characterized by elemental analysis, 1H-, 11B-, and 13C-NMR spectra and IR spectra. The carborane ligand, 7, was also characterized by single crystal X-ray diffraction. Compound 7 crystallizes in the monoclinic space group P2 1/ c with a=8.2357(19) Å, b=28.686(7) Å, c=9.921(2) Å; β=93.482(4)°; V=2339.5(9) Å 3, and Z=4. The final refinements of 7 converged at R=0.0736; wR=0.1494; GOF=1.372 for observed reflections. 相似文献
20.
The reaction of [ R-( R, R)]-(+) 589-[(η 5-C 5H 5){1,2-C 6H 4(PMePh) 2}Fe(NCMe)]PF 6 with (±)-AsHMePh in boiling methanol yields crystalline [ R-[( R)-( R, R)]-(+) 589)-[(η5-C5H5){1,2-C6H4(PMePh)2}Fe(AsHMePH)PF 6, optically pure, in ca. 90% yield, in a typical second-order asymmetric transformation. This complex contains the first resolved secondary arsine. Deprotonation of the secondary arsine complex with KOBu t at −65°C gives the diastereomerically pure tertiary arsenido-iron complex [ R-[( R),( R, R)]]-[((η 5-C 5H 5){1,2-C 6H 4(PMePh) 2}FeAsMePh] · thf, from which optically pure [ R-[( S),( R, R)]]-(+) 589-[(η 5-C 5H 5){1,2-C 6H 4(PMePh) 2}Fe(AsEtMePh)PF 6 is obtained by reaction with iodoethane. Cyanide displaces ( R)-(−) 589-ethylmethylphenylarsine from the iron complex, thereby effecting the asymmetric synthesis of a tertiary arsine, chiral at arsenic, from (±)-methylphenylarsine and an optically active transition metal auxiliary. 相似文献
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