Synthetic and structural investigations of monomeric dilithium boraamidinates and bidentate NBNCN ligands with bulky N-bonded groups

The dilithiated boraamidinate complexes [Li(2)[PhB(NDipp)(2)](THF)(3)] (7a) (Dipp = 2,6-diisopropylphenyl) and [Li(2)[PhB(NDipp)(N(t)Bu)](OEt(2))(2)] (7b), prepared by reaction of PhB[N(H)Dipp][N(H)R'] (6a, R' = Dipp; 6b, R' = (t)Bu) with 2 equiv of (n)BuLi, are shown by X-ray crystallography to have monomeric structures with two terminal and one bridging THF ligands (7a) or two terminal OEt(2) ligands (7b). The derivative 7a is used to prepare the spirocyclic group 13 derivative [Li(OEt(2))(4)][In[PhB(NDipp)(2)](2)] (8a) that is shown by an X-ray structural analysis to be a solvent-separated ion pair. The monoamino derivative PhBCl[N(H)Dipp] (9a), obtained by the reaction of PhBCl(2) with 2 equiv of DippNH(2), serves as a precursor for the synthesis of the four-membered BNCN ring [[R'N(H)](Ph)B(mu-N(t)Bu)(2)C(n)Bu] (10a, R' = Dipp). The X-ray structures of 6a, 9a, and 10a have been determined. The related derivative 10b (R' = (t)Bu) was synthesized by the reaction of [Cl(Ph)B(mu-N(t)Bu)(2)C(n)Bu] with Li[N(H)(t)Bu] and characterized by (1)H, (11)B, and (13)C NMR spectra. In contrast to 10a and 10b, NMR spectroscopic data indicate that the derivatives [[DippN(H)](Ph)B(NR')(2)CR(NR')] (11a: R =( t)Bu, R' = Cy; 11b: R = (n)Bu, R' = Dipp) adopt acyclic structures with three-coordinate boron atoms. Monolithiation of 10a produces the novel hybrid boraamidinate/amidinate (bamam) ligand [Li[DippN]PhB(N(t)Bu)C(n)Bu(N(t)Bu)] (12a).     

Substituent effects in the hydrosilylation of coordinated dinitrogen in a ditantalum complex: cleavage and functionalization of N2

The dinitrogen complex ([NPN]Ta)2(mu-eta1:eta2-N2)(mu-H)2, 1, (where [NPN] = (PhNSiMe2CH2)2PPh) undergoes hydrosilylation with primary and secondary alkyl- and arylsilanes, giving a new N-Si bond and a new terminal tantalum hydride derived from one Si-H unit. Various primary silanes can be employed to give isolable complexes of the general formula ([NPN]TaH)(mu-N-N-SiH(n)R(3-n))(mu-H)2(Ta[NPN]) (5, R=Bu, n = 2; 9, R=Ph, n = 2). Analogous complexes featuring secondary silanes are not isolable, because these products, and 5 and 9, are uniformly unstable toward reductive elimination of bridging hydrides as H2, followed by cleavage of the N-N bond to give ([NPN]TaH)(mu-N)(mu-N-SiH(n)R(3-n))(Ta[NPN]) (6, R=Bu, n = 2; 10, R=Ph, n = 2; 15, R=Ph, n = 1; 16, R=Ph and Me, n = 1). The bridging nitrido ligand in these complexes is itself a substrate for a second hydrosilylation when n = 2, and schemes leading to Ta(IV) complexes of the general formula ([NPN]Ta)2(mu-N-SiH2R)(mu-N-SiH2R') via elimination of H2 are reported (4, R=R'=Bu; 12, R=Bu, R' = Ph; 13, R=Bu, R' = CH2CH2SiH3). At this point, the general reaction manifold for these compounds ramifies, with distinct outcomes occurring for different R groups-[NPN] ligand amide migration from Ta to RSi affords 11, whereas stable complex 6 rearranges to give 7, in the presence of excess silane. Ethanediylbissilane reacts with 1 to give 14, isostructural to 7.     

Synthesis and coordination properties of new bis(phosphinomethyl)pyridine N,P,P'-trioxides

In a search for more hydrocarbon solvent soluble derivatives of the parent ligand, 2,6-[Ph(2)P(O)CH(2)](2)C(5)H(3)NO (1a), a series of new ligands, 2,6-[R(2)P(O)CH(2)](2)C(5)H(3)NO [R = Bz (1b); Tol (1c); Et (1d); Pr (1e); Bu (1f); Pn (1g); Hx (1h); Hp (1i); and Oct (1j)] and 2,6-[RR'P(O)CH(2)](2)C(5)H(3)NO [R = Ph, R' = Bz (2a); R = Ph, R' = Me (2b); R = Ph, R' = Hx (2c); R = Ph, R' = Oct (2d)], have been prepared by either Arbusov or Grignard substitutions on 2,6-bis(chloromethyl)pyridine followed by N-oxidation. The new ligands have been characterized by spectroscopic methods, and their coordination chemistry with selected lanthanide ions has been surveyed. Several 1:1 and 2:1 ligand/metal complexes have been isolated, and single-crystal X-ray diffraction analyses for Nd(2a)(NO(3))(3), Er(2a)(NO(3))(3), Yb(1d)(NO(3))(3), and [Nd(1c)(2)](NO(3))(3) are described. The new structural data are discussed in relation to the structures of complexes formed by 1a.     

Terminal nickel(ii) amide, alkoxide, and thiolate complexes containing amido diphosphine ligands of the type [N(o-C6H4PR2)2]- (R = Ph, (i)Pr, Cy)

A series of nickel(ii) complexes of the type [R-PNP]Ni(ER') ([R-PNP](-) = [N(o-C(6)H(4)PR(2))(2)](-); R = Ph, (i)Pr, Cy; E = NH, O, S; R' = Ph, (t)Bu) featuring unsupported, covalently bound pi-donor ligands have been prepared and characterized. The metathetical reactions of [R-PNP]NiCl (R = Ph, (i)Pr, Cy) with LiNHPh, NaOPh, or NaSPh, respectively, produced the corresponding anilide [R-PNP]Ni(NHPh), phenolate [R-PNP]Ni(OPh), and thiophenolate [R-PNP]Ni(SPh) derivatives. Treatment of [Ph-PNP]NiCl with either LiNH(t)Bu or NaO(t)Bu generated tert-butyl amide [Ph-PNP]Ni(NH(t)Bu) and tert-butoxide [Ph-PNP]Ni(O(t)Bu), respectively. In contrast, attempts to prepare analogous tert-butyl amide and tert-butoxide complexes of [(i)Pr-PNP](-) or [Cy-PNP](-) were not successful. Protonolysis studies of these nickel(ii)-heteroatom complexes revealed the basic reactivity of these pi-donor ligands. The basicity follows the order NH(t)Bu > O(t)Bu > NHPh > OPh > SPh. In addition to solution NMR spectroscopic data for all new compounds, X-ray structures of [(i)Pr-PNP]Ni(NHPh) and [(i)Pr-PNP]Ni(OPh) are presented.     

Synthesis,structure and ethylene polymerization of group 4 complexes with phosphinoamide ligands

Group 4 complexes containing diphosphinoamide ligands [Ph₂PNR]₂MCl₂ (3: R = ^tBu, M = Ti; 4: R = ^tBu, M = Zr; 5: R = Ph, M = Ti; 6: R = Ph, M = Zr) were prepared by the reaction of MCl₄ (M = Ti; Zr) with the corresponding lithium phosphinoamides in ether or THF. The structure of [Ph₂PN^tBu]₂TiCl₂ (3) was determined by X‐ray crystallography. The phosphinoamides functioned as η²‐coordination ligands in the solid state and the Ti? N bond length suggests it is a simple single bond. In the presence of modified methylaluminoxane or i‐Bu₃Al/Ph₃BC(C₆F₅)₄, catalytic activity of up to 59.5 kg PE/mol cat h bar was observed. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis, characterization, and ligand exchange studies of W(6)S(8)L(6) cluster compounds

Eleven organic Lewis bases were investigated as potential ligands (L) on W(6)S(8)L'(6) clusters by exploring ligand exchange reactions to form W(6)S(8)L(6) clusters. Six new homoleptic W(6)S(8)L(6) cluster complexes were prepared and characterized with L = tri-n-butylphosphine (P(n)Bu(3)), triphenylphosphine (PPh(3)), tert-butylisocyanide ((t)BuNC), morpholine, methylamine (MeNH(2)), and tert-butylamine ((t)BuNH(2)). While partial replacement of ligands occurred with diethylamine (Et(2)NH) and dibutylamine (Bu(2)NH), homoleptic clusters could not be prepared by these exchange reactions. When aniline, tribenzylamine, and tri-tert-butylphosphine were the potential ligands, no exchange was observed. From ligand exchange studies of these ligands and others previously studied, a thermodynamic series of binding free energies for ligands on W(6)S(8)L(6) clusters was established as the following: non-Lewis base solvents, aniline, P(t)()Bu(3), etc. < Et(2)NH, Bu(2)NH < (t)BuNH(2) < morpholine, piperidine < or = (n)BuNH(2), MeNH(2) < or = 4-tert-butylpyridine, pyridine < (t)BuNC < tricyclohexylphosphine (PCy(3)) < PPh(3), P(n)Bu(3) < or = triethylphosphine (PEt(3)). Structures of the new cluster complexes were determined by X-ray crystallography. The new compounds were also characterized by NMR spectroscopy and thermogravimetric analyses (TGA). The W-L bond orders and TGA data qualitatively agree with the thermodynamic series above.     

Synthesis and spectroscopic studies on organotin(IV) complexes of some pyrazoles and pyrazol-5-ones and their antibacterial activity

A series of organotin(IV) complexes of the general formula R_xSnCl_4?x.L (where R=Me, n?Bu, Ph; x = 2 or 3; L = pyrazole or pyrazol-5-one) have been prepared and characterized by elemental analyses, IR and NMR spectroscopy. The ligands used were found to coordinate with R₃SnCl species as monodentate ligands via the more reactive nitrogen atom, to give pentacoordinate tin complexes, whilst they may coordinate with R₂SnCl₂ species as bidentate ligands through the N–N linkage to give hexacoordinate tin complexes. These were demonstrated mainly by spectroscopic data. The tautomeric behaviour of organotin complexes of pyrazol-5-one ligands in inert (CDCl₃) and donor (DMSO-d₆) solvents were also studied. The complexes were screened against six species of bacteria.     

Applications of bis(1-R-imidazol-2-yl)disulfides and diselenides as ligands for main-group and transition metals: kappa2-(N,N) coordination, S-S bond cleavage, and S-S/E-E (E = S, Se) bond metathesis reactions

Bis(1-R-imidazol-2-yl)disulfides, (mim(R))2 (R = Ph, Bu(t)), and diselenides, (seim(Mes))2, serve as bidentate N,N-donor ligands for main-group and transition metals. For example, [kappa2-(mim(Bu)(t))2]MCl2 (M = Fe, Co, Ni, Zn), [kappa2-(mim(Ph))2]MCl2 (M = Co, Zn), [kappa2-(mim(Bu)(t))2]CuX (X = Cl, I), and [kappa2-(seim(Mes))2]MCl2 (M = Fe, Co, Ni) are obtained by treatment of (mim(Bu)(t))2 or (seim(Mes))2 with the respective metal halide and have been structurally characterized by X-ray diffraction. On the other hand, the zerovalent nickel complex Ni(PMe3)4 effects cleavage of the disulfide bond of (mim(Bu)(t))2 to give square-planar trans-Ni(PMe3)2(mim(Bu)(t))2 in which the (mim(Bu)(t)) ligands coordinate via nitrogen rather than sulfur, a most uncommon coordination mode for this class of ligands. Although [kappa2-(mim(R))2]MCl2 (M = Fe, Co, Ni, Zn) are not subject to homolytic cleavage of the S-S bond because the tetravalent state is not readily accessible, the observation that [kappa2-(mimPh)2]CoCl2 and [kappa2-(mim(Bu)(t))2]CoCl2 form an equilibrium mixture with the asymmetric disulfide [kappa2-(mim(Ph))(mim(Bu)(t))]CoCl2 indicates that S-S bond cleavage via another mechanism is possible. Likewise, metathesis between disulfide and diselenide ligands is observed in the formation of [kappa2-(mim(Bu)(t))(seim(Mes))]CoCl2 upon treatment of [kappa2-(mim(Bu)(t))2]CoCl2 with [kappa2-(seim(Mes))2]CoCl2.     

Hypervalent neutral O-donor ligand complexes of silicon tetrafluoride, comparisons with other group 14 tetrafluorides and a search for soft donor ligand complexes

The hypervalent adducts of SiF(4), trans-[SiF(4)(R(3)PO)(2)] (R = Me, Et or Ph), cis-[SiF(4){R(2)P(O)CH(2)P(O)R(2)}] (R = Me or Ph), cis-[SiF(4)(pyNO)(2)] and trans-[SiF(4)(DMSO)(2)] have been prepared from SiF(4) and the ligands in anhydrous CH(2)Cl(2), and characterised by microanalysis, IR and VT multinuclear ((1)H, (19)F, (31)P) NMR spectroscopy. The NMR studies show extensive dissociation at ambient temperatures in non-coordinating solvents, but mixtures of cis and trans isomers of the monodentate ligand complexes were identified at low temperatures. Crystal structures are reported for trans-[SiF(4)(R(3)PO)(2)] (R = Me or Ph), and cis-[SiF(4)(pyNO)(2)]. The GeF(4) analogues cis-[GeF(4){R(2)P(O)(CH(2))(n)P(O)R(2)}] (R = Me or Ph, n = 1; R = Ph, n = 2) were similarly characterised and the structures of cis-[GeF(4){R(2)P(O)CH(2)P(O)R(2)}] (R = Me or Ph) determined. The reaction of R(3)AsO (R = Me or Ph) with SiF(4) does not give simple adducts, but forms [R(3)AsOH](+) cations as fluorosilicate salts. SiF(4) adducts of some ether ligands (including THF, 12-crown-4) were also characterised by (19)F NMR spectroscopy in solution at low temperatures (～190 K), but are fully dissociated at room temperature. Attempts to isolate, or even to identify, SiF(4) adducts with phosphine or thioether ligands in solution at 190 K were unsuccessful, contrasting with the recent isolation and detailed characterisation of GeF(4) analogues. The chemistry of SiF(4) with these oxygen donor ligands, and with soft donors (P, As, S or Se), is compared and contrasted with those of GeF(4), SnF(4) and SiCl(4). The key energy factors determining stability of these complexes are discussed.     

Comments on the ring-opening polymerization of morpholine-2,5-dione derivatives by various metal catalysts and characterization of the products formed in the reactions involving R2SnX2, where X = OPr(i) and NMe2 and R = Bu(n), Ph and p-Me2NC6H4

(3S,6S)-3-Isopropyl-6-methyl-morpholine-2,5-dione (1), and (3S,6S)-3,6-dimethyl-morpholine-2,5-dione (2), do not enter into ring-opening polymerization reactions with metal catalyst precursors commonly employed for lactides, and with Sn(II) octanoate, only low molecular weight oligomers are obtained. Reactions with R2SnX2 compounds, where R = Ph, Bu(n) and p-Me2NC6H4 and X = OPr(i) or NMe2, reveal that ring-opening of the morpholine-2,5-diones does occur, but that polymerization is terminated by the formation of kinetically-inert products such as {Ph2Sn[mu,eta(3)-OCH(Me)CONCH(Pr(i))COOPr(i)]}2 (3), and {[Bu(n))2Sn[mu,eta(3)-OCH(Me)CONCH(Me)CONMe2]}2 (4), with elimination of HX. Ph3SnOPr(i) is seen to react reversibly with morpholine-2,5-diones in toluene-d8 by 1H NMR spectroscopy while (Bu(n))3SnNMe2 reacts by ring opening to give (Bu(n))3SnOCH(Me)C(O)NHCHMeC(O)NMe2. The new organotin compounds have been characterized by 1H, 13C{1H} and 118Sn NMR spectroscopy and compounds 1, 2, 3 and 4 by single crystal X-ray crystallography.     

Exploring stereogenic phosphorus: synthetic strategies for diphosphines containing bulky,highly symmetric substituents

Diphosphine ligands bearing highly symmetric, bulky substituents at a stereogenic P atom were prepared, exploiting established protocols, which include the use of chiral synthons such as 3,4-dimethyl-2,5-diphenyl-1,3,2-oxazaphospholidine-2-borane (3a) and phenylmethylchlorophosphine borane (10) and the enantioselective deprotonation of dimethylarylphosphine boranes. However, only (Bu(t)())(Me)PCH(2)CH(2)P(Bu(t)Me (8a) could be prepared from 3a. The diphosphines (S,S)-1,2-bis(mesitylmethylphosphino)ethane, ((S,S)-8b) and (S,S)-1,2-bis(9-anthrylmethylphosphino)ethane ((S,S)-8c), which contain 2,6-disubstituted aryl P-substituents, were prepared by Evans' sparteine-assisted enantioselective deprotonation of P(Ar)(Me)(2)(BH(3)) (Ar = mesityl or 9-anthryl), but the enantioselectivity did not exceed 37% ee. The asymmetrically substituted, methylene-bridged diphosphine (2R,4R)-(Ph)(CH(3))PCH(2)P(Mes)(CH(3)) ((2R,4R)-12) (Mes = mesityl) was prepared by the newly developed stereospecific reaction of the enantiomerically pure chlorophosphine borane PCl(Ph)(Me)(BH(3)) (10) with the racemic, monolithiated dimethylmesitylphosphine borane P(Mes)(Me)(CH(2)Li)(BH(3)). Diastereomerically pure (2R,4R)-12 was obtained with 86% ee. The rhodium(I) derivatives [Rh(COD)(P-P)]BF(4) containing the diphosphine ligands 8a, 8b, and 12, as well as the previously reported (S,S)-1,2-bis(1-naphthylphenylphosphino)ethane ((S,S)-8d), were prepared and tested in the enantioselective catalytic hydrogenation of acetamidocinnamates. The best catalytic result (98.6% ee) was obtained with [Rh(COD)(8d)](+) as catalyst and methyl Z-alpha-acetamidocinnamate as substrate. Some of the catalytic results are discussed in terms of the preferred conformations of the substituents at phosphorus, as calculated by molecular modeling.     

三烃基锡β-2, 8, 9-三氧杂-5-氮杂-1-锗杂三环[3.3.3.0^1.5]十一碳烷基(β-取代)丙酸酯的研究

本文合成了15个含锡锗杂恶唑烷化合物,N(CH~2CH~2O)~3GeCHR^1CH~2CO~2SnR(R=Cy~3, Bu~3^n, Ph~3, Cy~2Bu^n,CyBu~2^n; R^1=H, C~6H~5, p-CH~3C~6H~4, p-ClC~6H~4)。通过对产物的IR、1^HNMR、MS和元素的分析测定, 确定了它们的组成和结构。三丁基锡羧酸酯具有五配位的结构。生物活性测定结果表明, 这些化合物具有较好的杀螨和除草活性, 同时对植物病原菌也有一定的防治效果。     

Group 6 imido complexes supported by diamido-donor ligands

Reactions of the lithiated diamido-pyridine or diamido-amine ligands Li(2)N(2)N(py) or Li(2)N(2)N(am) with [W(NAr)Cl(4)(THF)] (Ar = Ph or 2,6-C(6)H(3)Me(2); THF = tetrahydrofuran) afforded the corresponding imido-dichloride complexes [W(NAr)(N(2)N(py))Cl(2)] (R = Ph, 1, or 2,6-C(6)H(3)Me(2), 2) or [W(NAr)(N(2)N(am))Cl(2)] (R = Ph, 3, or 2,6-C(6)H(3)Me(2), 4), respectively, where N(2)N(py) = MeC(2-C(5)H(4)N)(CH(2)NSiMe(3))(2) and N(2)N(am) = Me(3)SiN(CH(2)CH(2)NSiMe(3))(2). Subsequent reactions of 1 with MeMgBr or PhMgCl afforded the dimethyl or diphenyl complexes [W(NPh)(N(2)N(py))R(2)] (R = Me, 5, or Ph, 6), respectively, which have both been characterized by single crystal X-ray diffraction. Reactions of Li(2)N(2)N(py) or Li(2)N(2)N(am) with [Mo(NR)(2)Cl(2)(DME)] (R = (t)Bu or Ph; DME = 1,2-dimethoxyethane) afforded the corresponding bis(imido) complexes [Mo(NR)(2)(N(2)N(py))] (R = (t)Bu, 7, or Ph, 8) and [Mo(N(t)Bu)(2)(N(2)N(am))] (9).     

苯并噻唑 盐催化合成1,4-二羰基化合物

在苯并噻唑 盐和三乙胺存在下, 醛可以作为酰基负离子的合成等价物对α,β-不饱和酮进行Michael加成, 生成相应的1,4-二羰基化合物. 文中对 盐的制备, 催化反应条件及催化反应的机理进行了研究和讨论.     

Donor-stabilised cations, phosphinamide anions, and unusual oxidative cyclisation products from halogenated phosphoranimines and phosphinimines with a bulky 2,4,6-tri-tert-butylphenyl substituent at nitrogen

New aspects of the chemistry of the phosphoranimine Cl(3)P=NMes* (Mes* = 2,4,6-tri-tert-butylphenyl) (7) and the phosphinimine ClP=NMes* (2) have been explored. A cationic derivative of 7 was prepared from the reaction between this species and DMAP (DMAP = 4-dimethylaminopyridine) in the presence of the halide abstraction agent AgOTf (OTf = OSO(3)CF(3)) which yielded the donor-stabilized cation [DMAP-PCl(2)=NMes*](+) ([9](+)). When treated with tertiary phosphines (n)Bu(3)P or Ph(3)P, 7 was found to undergo a reductive dechlorination reaction to yield 2 and dichlorophosphoranes R(3)PCl(2) (R = (n)Bu (13a), Ph (13b)). The phosphinimine 2 reacts with Cl(-) sources to form the novel dichlorophosphinamide anion [Cl(2)PNMes*](-) ([14](-)) which was characterized in solution. Treatment of [Ph(4)P][14], generated in situ, with GaCl(3) or MeOTf regenerated 2 and provided further evidence for the formation of the anion [14](-). In addition, phosphoranimine 2 was found to undergo an unexpected oxidative cyclization reaction when treated with the oxygen transfer agent pyridine-N-oxide to yield a P-chlorophosphoryl-ox-3-azoline (18).     

Synthesis and characterisation of aluminium(III) and tin(II) complexes bearing quinoline-based N,N,O-tridentate ligands and their catalysis in the ring-opening polymerisation of ε-caprolactone

The synthesis and catalysis in the ring-opening polymerisation (ROP) of ε-caprolactone (ε-CL) of aluminium(iii) and tin(ii) complexes supported by quinoline-based N,N,O-tridentate ligands are reported. Reaction of 8-{RC(O)CH(2)P(Ph(2)) = N}C(9)H(6)N (R = Bu(t), 2; R = Ph, 3) with AlMe(3) gave [Al(Me(2)){OCR = CHP(Ph(2)) = N(8-C(9)H(6)N)}] (R = Bu(t), 4; R = Ph, 5). Treatment of 2 and 3 with Sn[N(SiMe(3))(2)](2) generated tin(ii) complexes [Sn{OC(R) = CHP(Ph(2)) = N(8-C(9)H(6)N)}{N(SiMe(3))(2)}] (R = Bu(t), 6; R = Ph, 7). A similar reaction of AlMe(3) with 8-{MeC(O)CH(2)C(Me) = N}C(9)H(6)N gave [Al(Me(2)){OC(Me) = CHC(Me) = NC(9)H(6)N}] (9). Compounds 2-9 were characterised by NMR spectroscopy and elemental analysis. The molecular structures of complexes 4, 6 and 9 were determined by single crystal X-ray diffraction techniques. Investigation of catalysis of complexes 4-7 and 9 in the ROP of ε-CL revealed that the aluminium complexes, 4, 5 and 9, are much more active than the tin(ii) complexes. The kinetic studies for the polymerisation of ε-CL catalysed by complexes 4, 5 and 9 in the presence of benzyl alcohol (BnOH) indicated that the polymerisations proceed with the first-order dependence on monomer concentration. The polymerisation was well controlled and gave a polymer with narrow molecular weight distribution.     

Zinc complexes of anionic NPPN and NP(S)PN ligands and rearrangement to the isomeric NPNP and NP(S)NP ligands in mercury complexes

The lithium (imido)diphosphineimide Li(Et2O)[DippNPhP-P((n)Bu)PhNDipp] (1) (Dipp = 2,6-(i)Pr2C6H3) undergoes simple metathesis reactions with equimolar amounts of zinc halides, ZnCl2 and (t)BuZnBr, to give the respective N,N'-chelated complexes {Zn(micro-Cl)[DippNPhP-P((n)Bu)PhNDipp]}2 (2) and (t)BuZn[NDippPhP-P((n)Bu)PhNDipp] (3). In contrast, the reaction of two equivalents of complex 1 with HgCl2 affords the rearranged bis(imidodiphosphinoamine) complex, Hg[PhP([double bond, length as m-dash]NDipp)(micro-NDipp)P((n)Bu)Ph]2 (4), where the ligand acts as a P-centered anion. The (imido)diphosphineimide backbone of remains intact on oxidation with elemental sulfur to afford the lithium (imido)diphosphineimine sulfide complex, Li(Et2O)[DippNPhP(S)-P((n)Bu)PhNDipp] (6). Reactions of 6 with group 12 metal halides show similar behaviour to those of complex 1. The N,N' chelated metathesis products RZn[DippNPhP(S)-P((n)Bu)PhNDipp] (7, R = Cl; 8, R = (t)Bu) are obtained on reaction with ZnCl2 and (t)BuZnBr, respectively. Isomerization of the ligand backbone occurs on reaction of 6 with HgCl2 to form the homoleptic P,S-chelated mercury complex Hg[Ph(S)P(=NDipp)(micro-NDipp)P((n)Bu)Ph]2 (9). Complexes 2, 3, 4, 6, 8 and 9 have been characterized by X-ray crystallography.     

Synthesis, structures of (aminopyridine)nickel complexes and their use for catalytic ethylene polymerization

A series of α-aminopyridines in the form of (2,6-C(6)H(3)N)(R(1))(CHR(2)NR(3)R(4)) (R(1) = R(2) = H R(3) = H R(4) = (i)Pr (L1a), R(4) = (t)Bu (L1b), R(4) = Ph (L1c), R(4) = 2,6-Me(2)C(6)H(3) (L1d), R(4) = 2,6-(i)Pr(2)C(6)H(3) (L1e), R(1) = R(2) = H R(3) = R(4) = Et (L1f), R(1) = H R(2) = Me R(3) = H R(4) = (i)Pr (L2a), R(4) = Ph (L2c), R(4) = 2,6-Me(2)C(6)H(3) (L2d), R(4) = 2,6-(i)Pr(2)C(6)H(3) (L2e), R(1) = Me R(2) = H R(3) = H R(4) = 2,6-(i)Pr(2)C(6)H(3) (L3e)) and β-aminopyridines in the form of (2-C(6)H(4)N)(CH(2)CH(2)NR(1)R(2)) (R(1) = H R(2) = (i)Pr (4a), R(2) = (t)Bu (L4b), R(1) = R(2) = Et (L4f)) have been prepared. Their corresponding halonickel complexes 1a-4f are synthesized by ligand substitution from (DME)NiBr(2) and the molecular structures are characterized. Four types of coordination modes include four-coordinate mononuclear species with one ligand, five-coordinate mononuclear species with two ligands, five-coordinate dinuclear species with two ligands, and a six-coordinate polymeric framework were determined by X-ray crystallography. Using methylaluminoxanes (MAO) as the activator, the nickel complexes can catalyze ethylene polymerization under moderate pressure and ambient temperature. The activity reaches 10(5) g PE mol(-1) Ni h. The PE products with high branching and high crystallinity have M(n) ~ 10(3) with PDI < 2.     

Silylchalcogenolates MESiR(t)Bu(2) (M = Na, Cu, Zn, Fe; E = S, Se, Te; R = tBu, Ph) and disilyldichalcogenides tBu2RSiE-ESiRtBu2 (E = S, Se, Te; R = tBu, Ph): synthesis, properties, and structures

The sodium silyl chalcogenolates NaESiR(t)Bu(2) (R = Ph, (t)Bu; E = S, Se, Te), accessible by the nucleophilic degradation of S, Se, or Te by the sodium silanides NaSiR(t)Bu(2) (R = Ph, (t)Bu), have been characterized by X-ray structure analysis. Protonolysis of the sodium silyl chalcogenolates yields the corresponding chalcogenols. The Cu and Zn chalcogenolates, [Cu(SSiPh(t)Bu(2))](4) and [ZnCl(SSi(t)Bu(3))(THF)](2), have been synthesized by metathesis reactions of CuCl with NaSSiPh(t)Bu(2) and of ZnCl(2) with NaSSi(t)Bu(3), respectively. The solid-state structures of the transition metal thiolates have been determined. The compounds (t)Bu(2)RSiE-ESiR(t)Bu(2) (R = Ph, (t)Bu; E = S, Se, Te) are accessible via air oxidation. With the exception of (t)Bu(3)SiS-SSi(t)Bu(3), these compounds were analyzed using X-ray crystallography and represent the first structurally characterized silylated heavy dichalcogenides. Oxidative addition of (t)Bu(3)SiTe-TeSi(t)Bu(3) to Fe(CO)(5) yields [Fe(TeSi(t)Bu(3))(CO)(3)](2), which has also been structurally characterized.     

五配位有机锡络合物的合成和表征

制备并表征了十个新型五配位有机锡络合物,用X射线衍射测定了它们的单晶结构,它们被指认炎二环氮染锡二氧杂壬烯类化合物.