共查询到20条相似文献,搜索用时 15 毫秒
1.
Xiang-Yang Liu Soraya Bouherour Heiko Jacobsen Helmut W. Schmalle Heinz Berke 《Inorganica chimica acta》2002,330(1):250-267
Lewis acid adducts of the hydrides cis- and trans-Re(CO)(PMe3)4H (1) and (2), mer-Re(CO)2(PMe3)3H (3), fac-Re(CO)2(PMe3)3H (4) and trans-Re(CO)3(PMe3)2H (5) were studied with BH3 and 9-borabicyclo[3,3,1] norbonane (BBNH). Using BH3·THF and (BBNH)2 1 and 2 afforded Re(CO)(PMe3)3(η2-BH4) (6) and Re(CO)(PMe3)3(η2-BBNH2) (7) as stable and isolable products. VT IR studies established for the reaction to 7 that BBNH first attaches in a pre-equilibrium to the OCO atom of 1 or 2. At higher temperatures ReH adduct formation occurs with instantaneous transformation to 7 and elimination of PMe3·BBNH. In a similar way, the hydrides 3 and 4 were converted with BH3·THF and (BBNH)2 to yield the stable complexes Re(CO)2(PMe3)2(η2-BH4) (8) and Re(CO)2(PMe3)2(η2-BBNH2) (9). The intermediacy of the η1-BH4 adducts mer-/fac-Re(CO)2(PMe3)3(η1-BH4) was confirmed by VT 1H, 31P NMR and VT IR experiments. The conversion of 5 with BH3·THF led to equilibria with adducts at the OCO terminus in trans position to H and with HRe as revealed by VT IR studies. Temperature dependent 31P equilibrium studies allowed to calculate ΔH=−4.9 kcal mol−1 and ΔS=+0.034 e.u. for this reaction. These adducts could not be isolated. Compound 5 does not react with (BBNH)2 even at elevated temperatures. DFT calculations were carried out to support the structures of the BH3 adducts of 5. In addition a vibrational analysis helped to unravel the IR band assignments of the involved compounds. DFT calculations on 8 confirmed its C2v structure. X-ray diffraction studies were carried out on single crystals of 6 and 7. 相似文献
2.
The thermal and photochemical reactions of CpRe(PPh3)2H4 and CpRe(PPh3)H4 (Cp = η5-C5H5) with PMe3, P(p-tolyl)3, PMe2Ph, DMPE, DPPE, DPPM, CO, 2,6-xylylisocyanide and ethylene have been examined. While CpRe(PPh3)2H2 is thermally inert, it will undergo photochemical substitution of one or two PPh3 ligands. With ethylene, substitution is followed by insertion of the olefin into the C-H bond of benzene, giving ethylbenzene. CpRe(PPh3)H4 undergoes thermal loss of PPh3, which leads to substituted products of the type CpRe(L) H4. Photochemically, reductive elimination of dihydrogen occurs preferentially. The complex trans-CpRe(DMPE)H2 was structurally characterized, crystallizing in the monoclinic space group P21/n (No. 14) with a = 6.249(6), b = 16.671(8), c = 13.867(7) Å, β = 92.11(6)°, V = 1443.7(2.9) Å and Z = 4. The complex trans-CpRe(PMe2Ph)2H2 was structurally characterized, crystallizing in the monoclinic space group P21/n (No. 14) with a = 7.467(3), b = 23.874(14), c = 11.798(6) Å, β = 100.16(4)°, V = 2070.2(3.4) Å3 and Z = 4. 相似文献
3.
Alan J. Lough Robert H. Morris Leonarda Ricciuto Thomas Schleis 《Inorganica chimica acta》1998,270(1-2):238-246
The complex [Ru(H2)(H)(PMe2Ph)4]PF6 (1) has been prepared by reaction of [Ru(H)(PMe2Ph)5] FP6 (2) in THF with 1 atm H2 and characterised by variable temperature 31P and 1H NMR. It undergoes four distinct fluxional processes listed in order of decreasing activation energy: (i) exchange of H2 in solution with the dihydrogen ligand above 273 K; (ii) isomerisation of cis and trans isomers of 1 above 230 K; (iii) exchange of H atoms between H2 and hydride in trans-1 above 180 K; (iv) rapid H2/hydride exchange in cis-1 to below 180 K. A single crystal X-ray diffraction study of 1 at 173 K shows that the complex has the cis geometry in the solid state but does not clearly reveal the positions of the hydrogen ligands. Complex 1 starts out as a catalyst of high activity for the selective hydrogenation of 1-alkynes to 1-alkenes (RC≡CH; R=11Bu, Ph) but it is rapidly deactivated, possibly because of formation of the enynyl complex [Ru(η3RC3CHR)(PMe2Ph)4]+. Complex 1 efficiently catalyzes the hydrogenation of internal alkynes (3-hexyne, 2-pentyne) to internal cis-alkenes with little deactivation, although some isomerisation of the alkene produced is observed. These observations are consistent with those of Nkosi, Coville, Albers and Singleton who reported that complex 2 must dissociate one PMe2Ph ligand to produce the species active for alkyne hydrogenation. Complex 2 catalyses these hydrogenations with slower initial rates than complex 1 but deactivates less readily. In contrast to 1, complex 2 does not appear to cause the isomerisation of internal alkenes. 相似文献
4.
The PMe2Ph ligands in the aquo-cations mer- [MCl2(H2O)(PMe2Ph)3][ClO4] rapidly exchange on the NMR time-scale giving coalescence in the 1H and 31P NMR spectra. Dissociation of the H2O ligand which is trans to PMe2Ph leads to a five- coordinate intermediate. This intermediate (M = Rh) is believed to be involved in the rapid reaction of [RhCl2(H2O)(PMe2Ph)3] [ClO4] with mer- [RhCl3(PMe2Ph)3] by a chloride transfer mechanism leading to total exchange of the PMe2Ph ligands. 相似文献
5.
Patrick W. Blosser Mario Calligaris David G. Schimpff Andrew Wojcicki 《Inorganica chimica acta》2001,320(1-2):110-116
Reactions of [(PPh3)2Pt(η3-CH2CCPh)]OTf with each of PMe3, CO and Br− result in the addition of these species to the metal and a change in hapticity of the η3-CH2CCPh to η1-CH2CCPh or η1-C(Ph)=C=CH2. Thus, PMe3 affords [(PMe3)3Pt(η1-C(Ph)=C=CH2)]+, CO gives both [trans-(PPh3)2Pt(CO)(η1-CH2CCPh)]+ and [trans-(PPh3)2Pt(CO)(η1-C(Ph)=C=CH2)]+, and LiBr yields cis-(PPh3)2PtBr(η1-CH2CCPh), which undergoes isomerization to trans-(PPh3)2PtBr(η1-CH2CCPh). Substitution reactions of cis- and trans-(PPh3)2PtBr(η1-CH2CCPh) each lead to tautomerization of η1-CH2CCPh to η1-C(Ph)=C=CH2, with trans-(PPh3)2PtBr(η1-CH2CCPh) affording [(PMe3)3Pt(η1-C(Ph)=C=CH2)]+ at ambient temperature and the slower reacting cis isomer giving [trans-(PPh3)(PMe3)2Pt(η1-C(Ph)=C=CH2)]+ at 54 °C . All new complexes were characterized by a combination of elemental analysis, FAB mas spectrometry and IR and NMR (1H, 13C{1H} and 31P{1H}) spectroscopy. The structure of [(PMe3)3Pt(η1-C(Ph)=C=CH2)]BPh4·0.5MeOH was determined by single-crystal X-ray diffraction analysis. 相似文献
6.
Martin P. Waugh Roger J. Mawby Amanda J. Reid Richard J. Carter Colin D. Reynolds 《Inorganica chimica acta》1995,240(1-2):263-271
Complexes Ru(CO)2 (CH=CHR) (C6H4X-4)L2 (R=tBu, Ph, OEt; X=H, Cl, OMe; L=PMe3, PMe2Ph, P(OMe)2Ph) in which the two phosphorus ligands are mutually cis (isomer 1) react readily with ligands tBuNC, CO and P(OMe)3 to give complexes in which one of the organic ligands has migrated onto a carbonyl ligand. Vinyl migration products (5) retain the mutually cis geometry of the phosphorus ligands, and are unstable: one of the decomposition products is the ketone RCH=CHC(O)C6H4X-4. Phenyl migration products (4) are stable and have the phosphorus ligands in mutually trans positions; an X-ray crystal structure of Ru(CO) (CNtBu) {C(O)Ph} (CH=CHPh) (PMe2Ph)2 was obtained. In both cases, the incoming ligand enters trans to the newly formed acyl ligand. Vinyl migration is favoured over aryl migration by electron-donating substituents on the vinyl ligand, electron-withdrawing substituents on the aryl ligand, good σ-donor phosphorus ligands and use of tBuNC as the incoming ligand. The rate of phenyl migration in Ru(CO)2(CH=CHPh)Ph(PMe2Ph)2 is independent of tBuNC concentration: k=1.5 × 10−3 s−1 at 20°C. Isomer 3 of complexes Ru(CO)2(CH=CHR) (C6H4X-4)L2 in which the phosphorus ligands are mutually trans is much less reactive towards migration reactions. The reactivity of isomer 1 is attributed to the steric strain of two mutually cis phosphorus ligands. 相似文献
7.
Protonation of Na3[Ta(CO)5] in liquid ammonia provides the thermally unstable Na[Ta(CO)5NH3], which may be isolated as the crystalline and deep violet salt [Ph4As][Ta(CO)5NH3]. Sodium amminepentacarbonyltantalate(1−) reacts with PMe3, PPh3, P(OMe)3, AsPh3, SbPh3, CNtBu and CN− at about 0°C in NH3/THF to give exclusively the corresponding [Ta(CO)5L]z. These have been isolated as tetraethylammonium salts in 54–84% yields. 相似文献
8.
The dinuclear Pt---Si complex {(Ph3P)Pt{μ-η2-H---SiH(IMP)]}2 (trans-1a–cis-1b=3:1; IMP=2-isopropyl-6-methylphenyl) reacted with basic phosphines such as 1,2-bis(diphenylphosphino)ethane (dppe) and dimethylphenylphosphine (PMe2Ph) to afford different dinuclear Pt---Si complexes with loss of H2, {(P)2Pt[μ-SiH(IMP)]}2 [P=dppe, trans-2a (major), cis-2b (trace); PMe2Ph, 3 (trans only)]. Complexes 2 and 3 were characterized by multinuclear NMR spectroscopy and X-ray crystallography (2a). In contrast, the reaction of 1a,b with the sterically demanding tricyclohexylphosphine (PCy3) afforded {(Cy3P)Pt{μ-η2-H---SiH(IMP)]}2 (trans-4a–cis-4b 2:1) analogous to 1a,b where the central Pt2Si2(μ-H)2 core remains intact but the PPh3 ligands have been replaced by PCy3. Complexes 4a and 4b was characterized by multinuclear NMR and IR spectroscopies. 相似文献
9.
Umberto Belluco Roberta Bertani Rino A. Michelin Mirto Mozzon Franco Benetollo Gabriella Bombieri Robert J. Angelici 《Inorganica chimica acta》1995,240(1-2):567-574
The chloro complexes trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4, react with 1-alkynes HC---C---R in the presence of NEt3 to afford the corresponding acetylide derivatives trans-[Pt(Me) (C---C---R) (PPh3)2] (R = p-tolyl (1), Ph (2), C(CH3)3 (3)). These complexes, with the exception of the t-butylacetylide complex, react with the chloroalcohols HO(CH2)nCl (n = 2, 3) in the presence of 1 equiv. of HBF4 to afford the alkyl(chloroalkoxy)carbene complexes trans-[Pt(Me) {C[O(CH2)nCl](CH2R) } (PPh3)2][BF4] (R = p-tolyl, N = 2 (4), N = 3 (5); R=Ph, N = 2 (6)). A similar reaction of the bis(acetylide) complex trans-[Pt(C---C---Ph)2(PMe2Ph)2] with 2 equiv. HBF4 and 3-chloro-1-propanol affords trans-[Pt(C---CPh) {C(OCH2CH2CH2Cl)(CH2Ph) } (PMe2Ph)2][BF4] (7). T alkyl(chloroalkoxy)-carbene complex trans-[Pt(Me) {C(OCH2CH2Cl)(CH2Ph) } (PPh3)2][BF4] (8) is formed by reaction of trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4 in HOCH2CH2Cl, with phenylacetylene in the presence of 1 equiv. of n-BuLi. The reaction of the dimer [Pt(Cl)(μ-Cl)(PMe2Ph)]2 with p-tolylacetylene and 3-chloro-1-propanol yields cis-[PtCl2{C(OCH2CH2CH2Cl)(CH2C6H4-p-Me}(PMe2Ph)] (9). The X-ray molecular structure of (8) has been determined. It crystallizes in the orthorhombic system, space group Pna21, with a = 11.785(2), B = 29.418(4), C = 15.409(3) Å, V = 4889(1) Å3 and Z = 4. The carbene ligand is perpendicular to the Pt(II) coordination plane; the PtC(carbene) bond distance is 2.01(1) Å and the short C(carbene)-O bond distance of 1.30(1) Å suggests extensive electronic delocalization within the Pt---C(carbene)---O moietry. 相似文献
10.
Vladimir F. Kuznetsov Glenn P. A. Yap Corinne Bensimon Howard Alper 《Inorganica chimica acta》1998,280(1-2):172-182
The reaction of Wilkinson's catalyst with NaOAr in toluene cleanly affords the corresponding aryloxide complexes Rh(PPh3)3OAr (1). In solution, 1 exists in equilibrium with PPh3 and the corresponding Rh(PPh3)2(π-ArO) (2). The addition of HOAr shifts the equilibrium completely toward the corresponding adducts 2·2HOAr, due to hydrogen bonding between the oxygen atom of the π-coordinated OAr ligand and two molecules of HOAr. Heating of 1a-d in toluene at 60–80°C leads to the elimination of HOAr with concomitant cyclometallation of a phenyl ring of one PPh3 ligand, affording mixtures of 1,2·2HOAr, a cyclometallated Rh complex and PPh3. At room temperature, a reverse reaction slowly occurs to give equilibrium mixtures of 1, 2 and PPh3. Complexes 1 readily with water, CO and H2, affording Rh2(PPh3)4(μ-OH)2, Rh(PPh3)2(CO)OAr (3) and HRh(PPh3)3, respectively. The latter complex was also obtained when complexes 1 were treated with methanol. The structures of the phenoxide complexes 1 and 2·2PhOH and of p-nitrophenoxide complex 3 were established by X-ray diffraction. 相似文献
11.
Kinetic and activation parameter data for the reactions of cct-Ru(H)2(CO)2(PPh3)2 (1) (cct = cis, cis, trans) in THF with thiols, CO and PPh3 to give cct-RuH(SR)(CO)2(PPh3)2, Ru(CO)3(PPh3)2 and Ru(CO)2(PPh3)2, respectively, reveal a common, rate-determining step, the initial dissociation of H2 from 1; the activated complex probably resembles the corresponding Ru(η2-H2) species. Reaction of Ru(H)2(dppm)2 (2) (as a cis/trans mixture, DPPM = bis(diphenylphosphino)methane) with thiols initially generated cis- and trans- RuH(SR) (dppm)2 with a rate that depends on both the type and concentration of thiol. The higher basicity of the hydride ligands in 2 (versus 1), which is demonstrated by deuterium exchange with CD3OD, gives rise in the thiol reaction to an initial protonation step prior to loss of H2. A species detected in the thiol reaction is possibly [RuH(η2-H2 (dppm)2]2, the anticipated intermediate for this reaction and for the hydrogen exchange with alcohol. A longer reaction of 2 with PhCH2SH gives solely cis-Ru(SCH2Ph)2(dppm)2. 相似文献
12.
Cis(or trans)-[RuCl2(CO)2(PPh3)2] react with two and one equivalents of AgBF4 to give the recently reported [Ru(CO)2(PPh3)2][BF4]2·CH2Cl2 (1) and novel [RuCl(CO)2(PPh3)2][BF4] · 1/2 CH2Cl2 (2), respectively. Cis-[RuCl2(CO)2(PPh3)2] also reacts with two equivalents of AgBF4 in the presence of CO to give [Ru(CO)3(PPh3)2][BF4]2 (3). Reactions of 1 and 2 with NaOMe and CO at 1 atm produce the carbomethoxy species [Ru(COOMe)2(CO)2(PPh3)2] (4) and [RuCl(COOMe)(CO)2(PPh3)2] (5), respectively. Complex 4 can also be formed from the reaction of 3 with NaOMe and CO. Alternatively, 4 is formed from cis-[RuCl2(CO)2(PPh3)2] with NaOMe and CO at elevated pressure (10 atm); if these reactants are refluxed under 1 atm of CO, [Ru(CO)3(PPh3)2] is the product. The reaction of [RuCl(CO)3(PPh3)2][AlCl4] with NaOMe provides an alternative route to the preparation of 5, but the product is contaminated with [RuCl2(CO)2(PPh3)2]. Compounds 1. 2, 4 and 5 have been characterised by IR, 1H NMR and analysis, whilst the formulation of 3 is proposed from spectroscopic data only. This account also examines the reactivity of [Ru(CO)2(PPh3)2][BF4]2 · CH2Cl2 with NaBH4, conc. HCl, KI and, finally, MeCOONa in the presence of CO. The products of these reactions, namely cis-[RuH2(CO)2(PPh3)2], cis-[RuCl2(CO)2(PPh3)2], cis-[RuI2(CO)2(PPh3)2] and [Ru(OOCMe)2(CO)2(PPh3)2], have been identified by comparison of their spectra with previous literature. 相似文献
13.
Reactions of cct-RuH(SR)(CO)2(PPh3)2 (1) (cct = cis, cis, trans) with R′SH provide cct-RuH(SR′)(CO)2(PPh3)2 (R = alkyl, aryl): based on described kinetic data, the proposed mechanism involves PPh3 loss, coordination of R′SH, intramolecular protonation of RS− by R′SH, and RSH elimination. The intramolecular protonation step circumvents a potentially slow RSH reductive elimination step. A similar mechanism is proposed for the thiol exchange reactions of cct-Ru(SR)2(CO)2(PPh3)2 (2). A corresponding dissociative mechanism is also proposed for the reaction of 1 with P(p-tolyl)3, which gives cct-RuH(SR)(CO)2(PPh3)(P(p-tolyl)3) and cct-RuH(SR)(CO)2− (P(p-tolyl)3)2. Other reactions described include the reactions of 1 with H2, CO, HCl and PPh3, and the reactions of 2 with P(p-tolyl)3 and H2. Exposure to light causes 2 to dimerize in solution. 相似文献
14.
The kinetics in heptane of displacement of the alkene ligands ethene and methyl acrylate from Ru(CO)4(η2-alkene) by P(OEt)3 have been measured. The reactions occur by reversible dissociation of the alkenes, and activation parameters are compared with those for dissociation of CO from Ru(CO)5 and for reactions of the corresponding Os complexes. A linear free energy relationship for ligand dissociation from Ru(CO)5, Ru(CO)4(C2H4) and Ru(CO)4(MA) has a gradient close to unity, indicating virtually complete bond breaking in the transition states. Competition parameters for reactions of what is probably a solvated Ru(CO)4S intermediate have been measured for the alkenes and P(OEt)3, and for eleven other P-donor nucleophiles. Correlations with the electronic and steric properties of the P-donors show negligible dependence on the electron donicity of the nucleophiles and a small but significant dependence on their sizes. The sizes were quantified by Tolman cone angles or by ‘cone angle equivalents’ derived directly from Brown's ligand repulsion energies (Er). These correlations compared with those, reported elsewhere, for reactions of the probably solvated intermediates Co2(CO)5(μ2-C2Ph2) and H3Re3(CO)11 formed by ligand dissociative processes. In all cases the discrimination between nucleophiles by the intermediates is weak confirming their high reactivity and the borderline nature of the mechanisms of these bimolecular reactions between Id and Ia. 相似文献
15.
Cristina Femoni Maria Carmela Iapalucci Giuliano Longoni Per H. Svensson 《Inorganica chimica acta》2002,330(1):111-117
The reaction of [N(PPh3)2]2[Ni6(CO)12] with Cu(PPh3)xCl (x=1, 2), as well as the degradation of [N(PPh3)2]2[H2Ni12(CO)21] with PPh3, affords the new and unstable dark orange–brown [N(PPh3)2]2[Ni9(CO)16].THF salt in low yields. This salt has been characterized by a CCD X-ray diffraction determination, along with IR spectroscopy and elemental analysis. The close-packed two-layer metal core geometry of the [Ni9(CO)16]2− dianion is directly related to that of the bimetallic [Ni6Rh3(CO)17]3− trianion and may be envisioned to be formally derived from the hcp three-layer geometry of [Ni12(CO)21]4− by the substitution of one of the two outer [Ni3(CO)3(μ−CO)3]2− layers with a face-bridging carbonyl group. 相似文献
16.
The reactions of [(H5C6)3P]2ReH6− with (CH3CN)3Cr(CO)3, (diglyme)Mo(CO)3 or (C3H7CN)3W(CO)3 led to the formation of [(H5C6)3P]2ReH6M(CO)3− (M = Cr, Mo, W) complexes. These have been characterized by IR and NMR spectroscopies, as well as elemental analyses. A single crystal X-ray diffraction study has also been carried out for the M = Cr complex as a K(18-crown-6)+ salt. The complex crystallizes as a THF monosolvate in the monoclinic space group P21/n with a = 22.323(6), B = 9.523(2), C = 27.502(5) Å, β = 104.98(2)0 and V = 5648 Å3 for Z = 4. The Re---Cr separation is 2.5745(12) Å, and the two phosphine ligands are oriented unsymmetrically. Although the hydride ligands were not found, the presence of three bridging hydrides and a dodecahedral coordination geometry about rhenium could be inferred. Low temperature 1H and 31P NMR spectroscopic studies did not reveal the low symmetry of the solid state structure. 相似文献
17.
Shakti L. Mukerjee Alberto A. Gonzalez Steven P. Nolan Telvin D. Ju Russell F. Lang Carl D. Hoff 《Inorganica chimica acta》1995,240(1-2):175-182
The enthalpies of reaction of HMo(CO)3C5R5 (R = H, CH3) with diphenyldisulfide producing PhSMo(CO)3C5R5 and PhSH have been measured in toluene and THF solution (R = H, ΔH= −8.5 ± 0.5 kcal mol−1 (tol), −10.8 ± 0.7 kcal mol−1 (THF); R = CH3, ΔH = −11.3±0.3 kcal mol−1 (tol), −13.2±0.7 kcal mol−1 (THF)). These data are used to estimate the Mo---SPh bond strength to be on the order of 38–41 kcal mol−1 for these complexes. The increased exothermicity of oxidative addition of disulfide in THF versus toluene is attributed to hydrogen bonding between thiophenol produced in the reaction and THF. This was confirmed by measurement of the heat of solution of thiophenol in toluene and THF. Differential scanning calorimetry as well as high temperature calorimetry have been performed on the dimerization and subsequent decarbonylation reactions of PhSMo(CO)3Cp yielding [PhSMo(CO)2Cp]2 and [PhSMo(CO)Cp]2. The enthalpies of reaction of PhSMo(CO)3Cp and [PhSMo(CO)2Cp]2 with PPh3, PPh2Me and P(OMe)3 have also been measured. The disproportionation reaction: 2[PhSMo(CO)2Cp]2 → 2PhSMo(CO)3Cp + [PhSMP(CO)Cp]2 is reported and its enthalpy has also been measured. These data allow determination of the enthalpy of formation of the metal-sulfur clusters [PhSMo(CO)nC5H5]2, N = 1,2. 相似文献
18.
Dean E. Rende Rouhyuk Kim Chris M. Beck Andrew Wojcicki 《Inorganica chimica acta》1995,240(1-2):435-439
The fluoro-hydrido-oxo complex [Re(F)(H)(O)Cyttp]+ (3, Cyttp = PhP(CH2CH2CH2PCy2)2) was prepared in high yield from [Re(H2)H4Cyttp]SbF6 (1(SbF6), NaSbF6 and acetone in toluene at reflux. Reaction chemistry of 3 has been studied and, where appropriate, compared with that of the related dihydrido-oxo complex [ReH2(O)Cyttp]+ (2). Unlike 2, which readily reacts with both CO and SO2, 3 was found to be inert to these reagents under comparable conditions. However, 3(SbF6) reacts with NaSbF6 at elevated temperature to afford the difluoro-oxo complex [ReF2(O)Cyttp]+ (4). 4 undergoes fluoride substitution by Cl− or Br− to yield [Re(X)(F)(O)Cyttp]+ (X = Cl (5, Br (6)). 5 can also be obtained by treatment of 6(BPh4) with LiCl. All of these complexes contain mer-Cyttp, and 3–6 contain trans fluoride and oxide ligands as inferred from spectroscopic data. 相似文献
19.
Anna Bonamartini Corradi Maria Rita Cramarossa Monica Saladini Luigi Pietro Battaglia Jolanda Giusti 《Inorganica chimica acta》1995,230(1-2):59-65
The chlorocadmate(II) systems of (H2me2pipz)[Cd2Cl6(H2O)2] (1) and (H2mepipz)2[Cd3Cl10(H2O)] (2) (L = me2pipz = N,N′-dimethylpiperazine; L′ = mepipz = N-methylpiperazine) were prepared and their structural and thermal properties investigated. Compound 1 is monoclinic, space group P21/c, A = 7.664(1), B = 7.472(4), C = 15.347(1) Å, β = 99.468(7)°, Z = 2, R = 0.024. The crystal structure consists of organic cations and infinite one-dimensional chains of [CdCl3(H2O)]n3− anions. Each Cd atom is octahedrally surrounded by bridged and terminal chlorine atoms and by a water molecule, which is in trans position with respect to the terminal chlorine atom. Inter- and intrachain hydrogen bond interactions between the terminal chlorine atoms and the water molecules contribute to the crystal packing. Compound 2 is orthorhombic, space group Cmc21, A = 15.286(3), B = 13.354(3), C = 13.154(3) Å, R = 0.023. The crystal structure consists of organic dications and infinite chains of [Cd2Cl6(CdCl4H2O]n4− units running along the [001] axis. Each unit is formed of regularly alternate six-coordinated Cd atoms, one of them linking one pentacoordinated Cd atom which completes its coordination througha water molecule. A strong hydrogen bond interaction involving the organic dication and the inorganic chain contributes to the crystal packing. Differential hydrogen bond interaction involving the organic dication and the inorganic chain contributes to the crystal packing. Differential scanning calorimetry measurements did not show the presence of any structural phase transitions. The structures are compared with those of (H2pipz)[Cd2Cl6(H2O)2] (3), (H2mepipz)[Cd2Cl6(H2O)2]·H2O (4) and (H2mepipz)[Cd2Cl6] (5) (L = pipz = piperazine, L′ = mepipz = N-ethylpiperazine). 相似文献
20.
Dietrich P. Steinhuebel Peter Fuhrmann Stephen J. Lippard 《Inorganica chimica acta》1998,270(1-2):527-536
A series of zirconium(IV) complexes, [ZrX2(XDK)], where XDK is the constrained carboxylate ligand m-xylylenediamine bis(Kemp's triacid imide), were prepared and structurally characterized. The solid state structure of the mononuclear carboxylate alkyl complex [Zr(CH2Ph)2(XDK)] reveals that one benzyl group is bonded in an η2-fashion to the metal center. The reactivity of [Zr(CH2Ph)2(XDK)] displays its electrophilic character toward nucleophiles strong enough to displace the η2-benzyl group. Thus, weak sigma donor ligands such as CO, alkynes and anilines do not react, whereas strong sigma donors, such as pyridines and isocyanides, rapidly form the monoadduct [Zr(CH2Ph)2(4-tert-butylpyridine)(XDK)] and [Zr{η2-2,6-Me2PhNCCH2Ph}2(XDK)], an η2-iminoacyl derivative, respectively. Attempts to prepare zirconium amido complexes with H2XDK generally afforded the eight-coordinate [Zr(XDK)2] complex but use of the small amido ligand precursorZr(NMe2)4 allowed [Zr(NMe2)2(4-tert-butylpyridine)(XDK)] to be isolated in good yield. 相似文献