Unusual interaction of alkynes with nine-vertex arachno-monocarbaboranes 4-CB8H14 and [4-CB8H13]-

Alkynes R(1)R(2)C(2) react with the neutral monocarbaborane arachno-4-CB(8)H(14) (1) at elevated temperatures (115-120 degrees C) under the formation of the derivatives of the ten-vertex dicarbaborane nido-5,6-C(2)B(8)H(12) (2) of general formula 9-Me-5,6-R1,R2-nido-5,6-C(2)B(8)H(9) (where R1,R2 = H,H 2a; Me,Me 2b; Et,Et 2c, H,Ph 2d, and Ph,Ph 2e) in moderate yields (26-52%). Side reaction with PhC(2)H also yields 1-Ph-6-Me-closo-1,2-C(2)B(8)H(8) (3d). In contrast, the reaction between [arachno-4-CB(8)H(13)](-) anion ((-)) and PhC(2)H produces a mixture of the closo anions [1-CB7H8]- (4-) and [1-CB6H7]- (5-) (yields 32 and 24%, respectively). Individual compounds were isolated and purified by liquid chromatography and characterized by NMR spectroscopy ((11)B, (1)H and (13)C) combined with two-dimensional [(11)B-(11)B]-COSY and (1)H-{(11)B(selective)}NMR techniques.     

Synthesis and Crystal Structure of 〔P(CH_2Ph)Ph_3〕〔PdWS_4(S_2CNC_4H_8)〕

1INTRoDUCTIoNThiomolybdate(thiotungstate)isafundamentalunitoPsomemolybdenumen-zymesandplaysanimportantroleincoordinationchemistryasaligandforothermet-alstoformanalogouscompoundsofmetalloproteinst'3.Recentlyinterestingnonlinearoptical(NLO)propertieshavebeendiscoveredforthetypeofMo(W)-Cu(Ag)-Sclusterst2.33.Bythevarioussyntheticmethodsseveralhundredmixedmetalclustersandcomplexes,Mo(W)-M-S(M=transitionmetal),havebeensynthesizedt'i.AmongthesecompoundsthecasesofMbeingCu,Ag,Feareusualwhile…     

Macropolyhedral boron-containing cluster chemistry. Synchrotron X-ray structural analysis of [(PMe2Ph)2Pd2B16H20(PMe2Ph)2] and [(PMe2Ph)3Pt2B16H18(PMe2Ph)]: models of intermediates to more condensed metallaboranes from the [(PMe2Ph)2PtB8H12] thermolysis system

Thermolyses of [(PMe2Ph)2PdB8H12] and [(PMe2Ph)2PtB8H12] respectively yield eighteen-vertex [(PMe2Ph)2Pd2B16H20(PMe2Ph)2] and [(PMe2Ph)3Pt2B16H18(PMe2Ph)], which exhibit structure models for probable successive precursive intermediates for the more condensed macropolyhedral metallaboranes [(PMe2Ph)4Pt3B14H16], [(PMe2Ph)2Pt2B12H16] and [(PMe2Ph)2Pt2B16H15(C6H4Me)(PMe2Ph)] that have previously been reported as products from [(PMe2Ph)2PdB8H12] thermolyses.     

Facile CH Bond Formation by Reductive Elimination at a Dinuclear Metal Site

The electronically unsaturated dirhenium complex [Re₂(CO)₈(µ‐AuPPh₃)(µ‐Ph)] ( 1 ) was obtained from the reaction of [Re₂(CO)₈{µ‐η²‐C(H)?C(H)nBu}(µ‐H)] with [Au(PPh₃)Ph]. The bridging {AuPPh₃} group was replaced by a bridging hydrido ligand to yield the unsaturated dirhenium complex [Re₂(CO)₈(µ‐H)(µ‐Ph)] ( 2 ) by reaction of 1 with HSnPh₃. Compound 2 reductively eliminates benzene upon addition of NCMe at 25 °C. The electronic structure of 2 and the mechanism of the reductive elimination of the benzene molecule in its reaction with NCMe were investigated by DFT computational analyses.     

Synthesis and Crystal Structure of FeCo_2(CO)_8(μ_3-S)〔P(OCH_2Ph)_3〕

1INTRODUCTIONBytreatingFeCo2(CO),(p,-S)withgroupVligands[L=PPh,,AsPh,,PBus",p(OEt),j,monosubstitutedderivativesFeCo2(CO),(p,-S)(L)havebeenobtained{1'2i.13C-NMRshowedthatthereplacementofCObyagroupVligandinFeCo,(CO),(p,-S)isatonecobaltatominthemonosubstitutedderivativet2).How-ever,thesubstitutedderivativeofFeCo,(CO),(p,-S)withP(OCH,Ph),hasnotbeenreportedanditscrystalstructurehasnotbeendetermined.WehavesynthesizedthetitlecompoundFeCo,(CO),(p,-S)[P(OCH,Ph),jandtestifiedth…     

A novel ribbon-candy-like supramolecular architecture of cadmium(II)-terephthalate polymer with giant rhombic channels: twofold interpenetration of the 3D 8(2)10-a net

The hydrothermal reaction of H2tp (tp = terephthalate), [Ph3PCH2Ph]Cl and water with Cd(O2CCH3)(2).2H2O gives rise to a novel ribbon-candy-like supramolecular architecture with twofold interpenetration of an unprecedented 3D 8(2)10-a net formed by polymer ([Ph3PCH2Ph][Cd(tp).Cl].2H2O]n containing giant rhombic channels, which displays strong fluorescent emission in the solid state.     

链状三核钼(钨)硫原子簇化合物[M3O2S8]^2^-的合成, 光谱和晶体结构

本文以[NH4]2MOnS4-n(M=Mo, w, n=0-2)为原料, 在酸性和中性条件下, 合成出九个新的三核不对称钼硫和钨硫原子簇状化合物L2[M3O2S8][L=(n-Bu)4N, Ph4P,PyC16H33, (CH3)3NC16H33, Et4N], 用元素分析, 红外光谱, 紫外光谱对簇合物进行了表征, 并测定了其中[(n-Bu)4N]2[Mo3O2S8]和[n-Bu)4N]2[W3O2S8]两个簇合物的晶体结构。本文又一次验证了钼(钨)硫成簇反应是分子内部电子转反应, 并提出了反应历程。     

Detection and reactivity of Pd((C8H14)PCH2 CH2 P(C8H14))(CHPhCH2Ph)(H) as determined by parahydrogen-enhanced NMR spectroscopy

Pd(bcope)(OTf)2 (where bcope is (C8H14)PCH2CH2P(C8H14)) is shown to react with an alkyne in the presence of parahydrogen to form alkyl hydrides, such as Pd(bcope)(CHPhCH2Ph)(H), that are detectable by NMR spectroscopy because the proton resonances of the alkyl arm appear with strongly enhanced signal strengths.     

Triphenylantimony(v) catecholates and o-amidophenolates: reversible binding of molecular oxygen

Novel neutral antimony(V) complexes were isolated as crystalline materials and characterized by IR and NMR spectroscopy: o-amidophenolate complexes [4,6-di-tert-butyl-N-(2,6-dimethylphenyl)-o-amidophenolato]triphenylantimony(V) (Ph3Sb[AP-Me], 1) and [4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-amidophenolato]triphenylantimony(v) (Ph3Sb[AP-iPr], 2); catecholate complexes (3,6-di-tert-butyl-4-methoxycatecholato)triphenylantimony(V) (Ph3Sb[(MeO)Cat], 3), its methanol solvate 3CH3OH (4); (3,6-di-tert-butyl-4,5-di-methoxycatecholato)triphenylantimony(V) (Ph3Sb[(MeO)2Cat], 5) and its acetonitrile solvate 5CH3CN (6). Complexes 1-7 were synthesized by oxidative addition of the corresponding o-iminobenzoquinones or o-benzoquinones to Ph3Sb. In the case of the phenanthrene-9,10-diolate (PhenCat) ligand, two different complexes were isolated: Ph3Sb[PhenCat] (7) and [Ph4Sb]+[Ph2Sb(PhenCat)2]- (8). Complexes 7 and 8 were found to be in equilibrium in solution. Molecular structures of 2, 4, 6, and 8 were determined by X-ray crystallography. Complexes 1-7 reversibly bind molecular oxygen to yield Ph3Sb[L-Me]O2 (9), Ph3Sb[L-iPr]O2 (10), Ph3Sb[(MeO)L']O2 (11), Ph3Sb[(MeO)2L']O2 (12) and Ph3Sb[PhenL']O2 (13), which contain five-membered trioxastibolane species (where L is the O,O',N-coordinated derivative of a 1-hydroperoxy-6-(N-aryl)-iminocyclohexa-2,4-dienol, and L' the O,O',O'-coordinated derivative of 6-hydroperoxy-6-hydroxycyclohexa-2,4-dienone). Complexes 9-13 were characterized by IR and 1H NMR spectroscopy and X-ray crystallography.     

(Ph)3PBr][Br7], [(Bz)(Ph)3P]2[Br8], [(n-Bu)3MeN]2[Br20], [C4MPyr]2[Br20], and [(Ph)3PCl]2[Cl2I14]: extending the horizon of polyhalides via synthesis in ionic liquids

The five polyhalides [(Ph)(3)PBr][Br(7)], [(Bz)(Ph)(3)P](2)[Br(8)], [(n-Bu)(3)MeN](2)[Br(20)], [C(4)MPyr](2)[Br(20)] ([C(4)MPyr] = N-butyl-N-methylpyrrolidinium), and [(Ph)(3)PCl](2)[Cl(2)I(14)] were prepared by the reaction of dibromine and iodine monochloride in ionic liquids. The compounds [(Ph)(3)PBr][Br(7)] and [(Bz)(Ph)(3)P](2)[Br(8)] contain discrete pyramidal [Br(7)](-) and Z-shaped [Br(8)](2-) polybromide anions. [(n-Bu)(3)MeN](2)[Br(20)] and [C(4)MPyr](2)[Br(20)] exhibit new infinite two- and three-dimensional polybromide networks and contain the highest percentage of dibromine ever observed in a compound. [(Ph)(3)PCl](2)[Cl(2)I(14)] also consists of a three-dimensional network and is the first example of an infinite polyiodine chloride. All compounds were obtained from ionic liquids as the solvent that, on the one hand, guarantees for a high stability against strongly oxidizing Br(2) and ICl and that, on the other hand, reduces the high volatility of the molecular halogens.     

Nickel complexes supported by quinoline-based ligands: synthesis, characterization and catalysis in the cross-coupling of arylzinc reagents and aryl chlorides or aryltrimethylammonium salts

Lithium and nickel complexes bearing quinoline-based ligands have been synthesized and characterized. Reaction of 8-azidoquinoline with Ph(2)PNHR (R = p-MeC(6)H(4), Bu(t)) affords N-(8-quinolyl)iminophosphoranes RNHP(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N) (1a, R = p-MeC(6)H(4); 1b, R = Bu(t). C(9)H(6)N = quinolyl)). Reaction of 1a with (DME)NiCl(2) generates a nickel complex [NiCl(2){N(8-C(9)H(6)N)[double bond, length as m-dash]P(Ph(2))NH(p-MeC(6)H(4))}] (2a). Treatment of 1b with (DME)NiCl(2) and following with NaH produces [NiCl{(1,2-C(6)H(4))P(Ph)(NHBu(t))[double bond, length as m-dash]N(8-C(9)H(6)N)}] (4). Complex 4 was also obtained by reaction of (DME)NiCl(2) with [Li{(1,2-C(6)H(4))P(Ph)(NHBu(t))[double bond, length as m-dash]N(8-C(9)H(6)N)}] (5) prepared through lithiation of 1b. Reaction of 2-PyCH(2)P(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N) (6, Py = pyridyl) and PhN[double bond, length as m-dash]C(Ph)CH(2)P(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N) (8), respectively, with (DME)NiCl(2) yields two five-coordinate N,N,N-chelate nickel complexes, [NiCl(2){2-PyCH(2)P(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N)}] (7) and [NiCl(2){PhN[double bond, length as m-dash]C(Ph)CH(2)P(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N)}] (9). Similar reaction between Ph(2)PCH(2)P(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N) (10) and (DME)NiCl(2) results in five-coordinate N,N,P-chelate nickel complex [NiCl(2){Ph(2)PCH(2)P(Ph(2))[double bond, length as m-dash]N(8-C(9)H(6)N)}] (11). Treatment of [(8-C(9)H(6)N)N[double bond, length as m-dash]P(Ph(2))](2)CH(2) (12) [prepared from (Ph(2)P)(2)CH(2) and 2 equiv. of 8-azidoquinoline] with LiBu(n) and (DME)NiCl(2) successively affords [NiCl{(8-C(9)H(6)N)NP(Ph(2))}(2)CH] (13). The new compounds were characterized by (1)H, (13)C and (31)P NMR spectroscopy (for the diamagnetic compounds), IR spectroscopy (for the nickel complexes) and elemental analysis. Complexes 2a, 4, 7, 9, 11 and 13 were also characterized by single-crystal X-ray diffraction techniques. The nickel complexes were evaluated for the catalysis in the cross-coupling reactions of arylzinc reagents with aryl chlorides and aryltrimethylammonium salts. Complex 7 exhibits the highest activity among the complexes in catalyzing the reactions of arylzinc reagents with either aryl chlorides or aryltrimethylammonium bromides.     

Synthesis of linear and cyclic carbophosphazenes via an oxidative chlorination strategy

The use of a mild, oxidative chlorination route for the synthesis of linear and cyclic carbophosphazenes is described. For example, chlorination of the linear PNCN chain Ph(2)P-N=C(Ph)-N(SiMe(3))(2) (1) with C(2)Cl(6) led to the clean formation of the previously known 8- and 6-membered rings [Ph(2)PNC(Ph)N](2) (2) and [Ph(2)PNC(Ph)NP(Ph)(2)N] (3), respectively. In a similar fashion, the N-alkyl-substituted PNCN derivatives, Ph(2)P-N=C(Ph)-N((t)Bu)SiMe(3) (4) and Ph(2)P-N=C(Ph)-N(i)Pr(2) (7) were readily converted by C(2)Cl(6) into the halogenated derivatives ClPh(2)P=N-C(Ph)=N(t)Bu (5) and [ClPh(2)P=N=C(Ph)-N(i)Pr(2)]Cl (8), respectively. Protonation of 5 was accomplished using HCl and gave the carbophosphazenium salt [ClPh(2)P=N-C(Ph)=N((t)Bu)H]Cl (6). In addition, the isolation of a rare 8-membered P(2)N(4)C(2) heterocycle [(Cl(3)P=N)ClPNC(Ph)NP(Cl)(2)NC(Ph)N] (9) from the reaction of PCl(5) and Li[PhC(NSiMe(3))(2)] is reported. Treatment of 9 with one equivalent of GaCl(3) led to the discovery of an unusual Lewis acid-induced ring contraction reaction whereby the (PNCN)(2) ring in 9 is converted into the novel 6-membered P(2)N(3)C heterocyclic adduct [(Cl(3)P=N)ClPNP(Cl)(2)NC(Ph)N].GaCl(3) (10) with concomitant release of PhCN. Structural characterization of compounds 1, 5, 6, and 8-10 by single-crystal X-ray diffraction is also provided.     

Proton-coupled electron-transfer reduction of dioxygen catalyzed by a saddle-distorted cobalt phthalocyanine

Proton-coupled electron-transfer reduction of dioxygen (O(2)) to afford hydrogen peroxide (H(2)O(2)) was investigated by using ferrocene derivatives as reductants and saddle-distorted (α-octaphenylphthalocyaninato)cobalt(II) (Co(II)(Ph(8)Pc)) as a catalyst under acidic conditions. The selective two-electron reduction of O(2) by dimethylferrocene (Me(2)Fc) and decamethylferrocene (Me(10)Fc) occurs to yield H(2)O(2) and the corresponding ferrocenium ions (Me(2)Fc(+) and Me(10)Fc(+), respectively). Mechanisms of the catalytic reduction of O(2) are discussed on the basis of detailed kinetics studies on the overall catalytic reactions as well as on each redox reaction in the catalytic cycle. The active species to react with O(2) in the catalytic reaction is switched from Co(II)(Ph(8)Pc) to protonated Co(I)(Ph(8)PcH), depending on the reducing ability of ferrocene derivatives employed. The protonation of Co(II)(Ph(8)Pc) inhibits the direct reduction of O(2); however, the proton-coupled electron transfer from Me(10)Fc to Co(II)(Ph(8)Pc) and the protonated [Co(II)(Ph(8)PcH)](+) occurs to produce Co(I)(Ph(8)PcH) and [Co(I)(Ph(8)PcH(2))](+), respectively, which react immediately with O(2). The rate-determining step is a proton-coupled electron-transfer reduction of O(2) by Co(II)(Ph(8)Pc) in the Co(II)(Ph(8)Pc)-catalyzed cycle with Me(2)Fc, whereas it is changed to the electron-transfer reduction of [Co(II)(Ph(8)PcH)](+) by Me(10)Fc in the Co(I)(Ph(8)PcH)-catalyzed cycle with Me(10)Fc. A single crystal of monoprotonated [Co(III)(Ph(8)Pc)](+), [Co(III)Cl(2)(Ph(8)PcH)], produced by the proton-coupled electron-transfer reduction of O(2) by Co(II)(Ph(8)Pc) with HCl, was obtained, and the crystal structure was determined in comparison with that of Co(II)(Ph(8)Pc).     

SHOP-type nickel complexes with alkyl substituents on phosphorus, synthesis and catalytic ethylene oligomerization

The beta-keto phosphorus ylides (n-Bu)3P=CHC(O)Ph 6, (t-Bu)2PhP=CHC(O)Ph 7, (t-Bu)Ph2P=CHC(O)Ph 8, (n-Bu)2PhP=CHC(O)Ph 9, (n-Bu)Ph2P=CHC(O)Ph 10, Me2PhP=CHC(O)Ph 11 and Ph3P=CHC(O)(o-OMe-C6H4) 12 have been synthesized in 80-96% yields. The Ni(II) complexes [NiPh{Ph2PCH...C(...O)(o-OMeC6H4)}(PPh3)] 13, [NiPh{Ph(t-Bu)PCHC(O)Ph}(PPh3)] 15, [NiPh{(n-Bu)2PCH...C(...O)Ph}(PPh3)] 16 and [NiPh{Ph(n-Bu)PCH...C(...O)Ph}(PPh3)] 17 have been prepared by reaction of equimolar amounts of [Ni(COD)2] and PPh3 with the beta-keto phosphorus ylides 12 or 8-10, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. NMR studies and the crystal structure determination of 13 indicated an interaction between the hydrogen atom of the C-H group alpha to phosphorus and the ether function. The complexes [NiPh{Ph2PCHC(O)Ph}(Py)] 18, [NiPh{Ph(t-Bu)PCHC(O)Ph}(Py)] 19, [NiPh{(n-Bu)2PCH...C(...O)Ph}(Py)] 20, [NiPh{Ph(n-Bu)PCH...C(...O)Ph}(Py)] 21 and [NiPh{Me2PCH...C(...O)Ph}(Py)] 22 have been isolated from the reactions of [Ni(COD)2] and an excess of pyridine with the -keto phosphorus ylides Ph3PCH=C(O)Ph 3 or 8-11, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. Ligands 3, 8, 10 and 12 have been used to prepare in situ oligomerization catalysts by reaction with one equiv. of [Ni(COD)2] and PPh3 under an ethylene pressure of 30 or 60 bar. The catalyst prepared in situ from 12, [Ni(COD)2] and PPh3 was the most active of the series with a TON of 12700 mol C2H4 (mol Ni)-1 under 30 bar ethylene. When the beta-keto phosphorus ylide 8 was reacted in situ with three equiv. of [Ni(COD)2] and one equiv. of PPh3 under 30 bar of ethylene, ethylene polymerization was observed with a TON of 5500 mol C2H4 (mol Ni)-1.     

Theoretical Studies on the Ground State and Excited State of 2,70-(Ethylene)-bis-8-hydroxyquinoline

Dielectric relaxation method was employed to study the properties of oxygen ion diffusion and phase transition in the oxide-ion conductors (La1-xLnx)2Mo2O9 (Ln=Nd, Gd, x=0.05-0.25). Two dielectric loss peaks were observed: peak Pd at about 600 K and peak Ph around 720 K. Peak Pd is a relaxational peak and associated with the short-range diffusion of oxygen ions, while peak Ph hardly changes its position and dramatically decreases in height with increasing frequency, exhibiting non-relaxational nature. With increasing Ln3+ concentration, the heights of peak Ph and Pd increase at first and then decrease after passing a maximum at 15% doping. It is suggested that peak Ph is related to the phase transition of a static disordered state to a dynamic disordered state in oxygen ions/vacancies distribution. It is found that the 15%Gd or 15%Nd doped La2Mo2O9 samples exhibit the highest conductivity in accordance with the highest height of peak Pd at this doping content.     

Formation of a hybrid compound composed of a saddle-distorted Tin(IV)-porphyrin and a Keggin-type heteropolyoxometalate to undergo intramolecular photoinduced electron transfer

Nonplanar Sn(IV)-porphyrin complexes, [Sn(TMPP(Ph)(8))-Cl(2)] (1) and [Sn(TMPP(Ph)(8))(OMe)(2)] (2) (TMPP(Ph)(8): 5,10,15,20-tetrakis(4-methoxyphenyl)-2,3,7,8,12,13,17,18-octaphenylporphyrinato), were prepared and characterized by spectroscopic and electrochemical methods together with X-ray crystallography. Variable-temperature (1)H NMR study revealed that the coordination of the methoxo ligand of 2 is weak enough in solution to enhance the axial ligand exchange with a Keggin-type phosphotungstate (α-[PW(12)O(40)](3-)) due to the steric stress between the axial methoxo ligand and the peripheral phenyl groups of the porphyrin ligand. The formation of a novel 1:1 donor-acceptor complex, [Sn(TMPP(Ph)(8))(OMe)(α-[PW(12)O(40)])](2-) (4) was confirmed by (1)H NMR and UV-vis spectral titrations, and also by MALDI-TOF-MS measurements. Electrochemical measurements for the donor-acceptor complex in PhCN revealed that the Sn(IV)-TMPP(Ph)(8) moiety acts as an electron donor and the α-[PW(12)O(40)](3-) moiety acts as an electron acceptor and that the energy level of the electron-transfer (ET) state of the 1:1 complex (1.17 eV) is lower than that of the triplet excited states of the SnTMPP(Ph)(8) complex (1.31 eV). Femtosecond and nanosecond laser flash photolysis measurements indicate that intersystem crossing from the singlet excited sate to the triplet excited state occurs followed by intramolecular photoinduced electron transfer from the triplet excited state of the Sn(IV)-TMPP(Ph)(8) moiety to the α-[PW(12)O(40)](3-) moiety in the 1:1 complex in benzonitrile.     

N, C and Sn NMR and other spectroscopic studies of 8-quinolinol, its O- and N-methyl derivatives, and chelate di- and tri-organotin(IV) complexes

The nature of the 8-quinolinato ligand in various forms has been examined by ¹⁵N, ¹³C and ¹¹⁹Sn NMR spectroscopy, with evidence also from electronic spectroscopy. These forms include 8-quinolinol (HQ), 8-quinolinate, the 8-hydroxyquinolinium ion, O- and N-methyl derivatives, 8-methoxyquinoline (MeQ), the zwitterionic N-methylquinolinium-8-olate and the N-methylquinolinium ion, and the chelating ligand in organotin(IV) complexes. The ¹⁵N shift from MeQ to HQ affords a measure of the intramolecular hydrogen bonding in HQ. The ¹⁵N shifts and ²J(¹⁵N¹H) couplings afford criteria of chelation, and the O- and N-methyl compounds provide useful reference points for its assessment. Evidence for chelation is demonstrated in three groups of compounds, [SnR₂Q₂] (R = Me, Et, Buⁿ, Octⁿ or Ph), [SnR₃Q] (R = Me, Et, Buⁿ or Ph) and [SnR₂ClQ] (R = Me, Et, Buⁿ or Octⁿ), the ¹⁵N and ¹¹⁹Sn shielding increasing from the [SnR₃Q] to the [SnR₂Q₂] compounds.     

二(β-羟亚胺)二氯化钛配合物的合成及催化乙烯聚合

报道了3个β-羟亚胺配体(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂CH(Ph)OH(1a), (2,6-^emPr₂C₆H₃)N＝C·(Ph)CH₂C(Ph)₂OH(1b)和(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂C(C₁₂H₈)OH(1c)及其二(β-羟亚胺)二氯化钛配合物[(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂CH(Ph)O]₂TiCl₂(2a), [(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂C(Ph)₂O]₂·TiCl₂(2b)和[(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂C(C₁₂H₈)O]₂TiCl₂(2c)的合成, 并对其结构进行了表征. 在助催化剂甲基铝氧烷(MAO)作用下, 以化合物2b为主催化剂, 研究了Al/Ti摩尔比、 反应时间、 温度和聚合压力等对乙烯聚合的影响, 发现该催化体系在较宽的反应条件下均可得到很高分子量的聚乙烯, 熔点均在140℃左右. 以化合物2a~2c为主催化剂对乙烯进行催化聚合, 发现在β碳位上取代基的立体位阻对催化剂活性有很大影响. 当化合物2b上引入2个苯基取代基时, 催化剂显示出最佳催化活性.     

Unprecedented gold-tellurolate clusters [Au(8)(mu-TeR)(8)(PR'(3))(4)

The reaction of [AuCl(PR'3)] with KTeR, prepared from RTeTeR and K-selectride, gives the gold-tellurolate clusters [Au8(mu-TeR)8(PR'3)4] (R = Ph, Tol; PR'3 = PPh3, PPh2py) in high yield. This result contrasts with the one obtained from the reaction with thiolates or selenolates, from which mononuclear complexes are synthesized. The structures of these species have been determined and consist on three layers of gold and tellurium atoms in the ratio Au3Te2:Au2Te4:Au3Te2. There are short gold...gold interactions ranging from 2.9463(7) to 3.31132(7) A, and the clusters are composed of di- and tri-coordinated gold centers. The result is unprecedented in gold-chalcogenolate chemistry from which mononuclear species are expected and represents one of the few examples of gold-tellurolate derivatives. These species show an interesting luminescent behavior in the solid state (at 77 K) and in solution (both at 298 and 77 K).     

Methanolysis and phenolysis routes to Fe6, Fe8, and Fe1) complexes and their magnetic properties: a new type of Fe8 ferric wheel

Alcoholysis of preformed tetranuclear and hexanuclear iron(III) clusters has been employed for the synthesis of four higher-nuclearity clusters. Treatment of [Fe(4)O(2)(O(2)CMe)(7)(bpy)(2)](ClO(4)) with phenol affords the hexanuclear cluster [Fe(6)O(3)(O(2)CMe)(9)(OPh)(2)(bpy)(2)](ClO(4)) (1). Reaction of [Fe(6)O(2)(OH)(2)(O(2)CR)(10)(hep)(2)] (R = Bu(t) or Ph) with PhOH affords the new "ferric wheel" complexes [Fe(8)(OH)(4)(OPh)(8)(O(2)CR)(12)] [R = Bu(t) (2) or Ph (3)]. Complexes 2 and 3 exhibit the same structure, which is an unprecedented type for Fe(III). In contrast, treatment of [Fe(6)O(2)(OH)(2)(O(2)CBu(t))(10)(hep)(2)] with MeOH leads to the formation of [Fe(10)(OMe)(20)(O(2)CBu(t))(10)] (4), which exhibits the more common type of ferric wheel seen in analogous complexes with other carboxylate groups. Solid-state variable-temperature magnetic susceptibility measurements indicate spin-singlet ground states for complexes 2 and 4. The recently developed semiempirical method ZILSH was used to estimate the pairwise exchange parameters (J(AB)) and the average spin couplings S(A)[empty set].S(B)[empty set] between the Fe(III) centers, providing a clear depiction of the overall magnetic behavior of the molecules. All exchange interactions between adjacent Fe(III) atoms are antiferromagnetic.