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1.
The fluorination of [MeAlN(2,6-i-Pr2C6H3)]31 using 1 and 2 eq., respectively, trimethyltin fluoride leads to the mono- and difluoro compounds, [FAl(MeAl)2(N(2,6-i-Pr2C6H3))3]·2THF 2 and [(FAl)2MeAl(N(2,6-i-Pr2C6H3))3]·3THF 3, where each methyl group can be selectively exchanged for terminal fluorine atoms (AlF). The reaction of 1 and 3 eq. of trimethyltin fluoride leads to the trifluoro compound [FAlN(2,6-i-Pr2C6H3)]3·3THF 4 and [Me2SnN(2,6-i-Pr2C6H3)]25 as a by-product. The core of compound 5 consists of a tin-nitrogen four-membered Sn2N2 ring.  相似文献   

2.
The synthesis of lanthanide hydroxo complexes stabilized by a carbon-bridged bis(phenolate) ligand 2,2’-methylene-bis(6-tert-butyl-4-methylphenoxo) (MBMP2−) was described, and their reactivity toward phenyl isocyanate was explored. Reactions of (MBMP)Ln(C5H5)(THF)2 with a molar equiv. of water in THF at −78 °C afforded the bis(phenolate) lanthanide hydroxides as dimers [{(MBMP)Ln(μ-OH)(THF)2}2] [Ln = Nd (1), Yb (2)] in high yields. Complexes 1 and 2 reacted with phenyl isocyanate in THF, after workup, to give the desired O−H addition products, [(MBMP)Ln(μ-η12-O2CNHPh)(THF)2]2 [Ln = Nd (3), Yb (4)] in excellent isolated yields. These complexes were well characterized, and the molecular structures of complexes 2 to 4 were determined by X-ray crystallography. The ytterbium atom in complex 2 is coordinated to six oxygen atoms to form a distorted octahedral geometry, whereas each metal center in complexes 3 and 4 is seven-coordinated, and the coordination geometry can be best described as a distorted pentagonal bipyramid.  相似文献   

3.
A reaction of Sc, Y, and Yb amidopyridinate dichlorides with the corresponding amount of LiCH2SiMe3 was used to synthesize bis(trimethylsilylmethyl) complexes (Ap)Ln(CH2SiMe3)2-(THF) (Ap is N-mesityl-6-(2,4,6-triisopropylphenyl)pyridine-2-amide (Ap9Me), Ln = Y (2); Ap is N-(2,6-diisopropylphenyl)-6-(2,4,6-triisopropylphenyl)pyridine-2-amide (Ap*), Ln = Sc (3), Yb (4)). An exchange reaction of yttrium amidopyridinate dichloride derivative 1 with 4 equiv. of ButLi in hexane gave the corresponding di-tert-butyl derivative Ap9MeY(But)2(THF) (5). Molecular structures of complexes 3 and 4 were established by X-ray diffraction. A method of the ligand solid angles was used to calculate the completion degree of the metal atom coordination sphere for the series of isomorphic derivatives (Ap*)Ln(CH2SiMe3)2(THF) containing the central metal ions with different ionic radii (Sc, Y, Yb, Lu). According to this method, the amidopyridinate ligand solid angle in these complexes virtually does not vary, while the solid angles of coordinated THF molecule and alkyl ligands vary within a wide range.  相似文献   

4.
Based on two β-enaminoketonato ligands [ArNC(CH3)C(H)C(CF3)OH] (L1, Ar = 2,6-Me2C6H3; L2, Ar = 2,6-i-Pr2C6H3), their mono(β-enaminoketonato)nickel (II) complexes [(ArNC(CH3)C(H)C(CF3)O)Ni(Ph)(PPh3)] (1, Ar = 2,6-Me2C6H3; 3, Ar = 2,6-i-Pr2C6H3) and bis(β-enaminoketonato)nickel (II) complexes [(ArNC(CH3)C(H)C(CF3)O)2Ni] (2, Ar = 2,6-Me2C6H3; 4, Ar = 2,6-i-Pr2C6H3) have been synthesized and characterized. The molecular structures of complex 1, 2 and 4 have been confirmed by single-crystal X-ray analyses. After being activated with methylaluminoxane (MAO) these catalytic precursors 1-4 could polymerize norbornene to afford addition-type polynorbornene (PNB). Interestingly, catalytic activities and PNB productivity were greatly enhanced due to the introduction of strong electron-withdrawing group - trifluoro methyl into the ligands. Catalytic activities, polymer yield, Mw and Mw/Mn of PNB have been investigated under various reaction conditions.  相似文献   

5.
Treatment of LnCl3 with [(SiMe3)2NC(NiPr)2]Li in 1:2 molar ratio afforded the soluble bis(guanidinate)lanthanide chlorides {[(SiMe3)2NC(NiPr)2]2Ln(μ-Cl)}2 (Ln=Y (1), Nd (2)). Amination of 1 and 2 with two equivalents of LiN(iPr)2 in a mixture solution of toluene and hexane gave [(SiMe3)2NC(NiPr)2]2LnN(iPr)2 (Ln=Y (3), Nd (4)) in good isolated yields. The single-crystal structural analyses of 2 and 3 revealed that the coordination geometries of lanthanide metals are best described as a distorted pseudo-octahedron and a pseudo-pyramid, respectively. Complexes 3 and 4 exhibited extremely high activity for the polymerizations of ε-caprolactone and methyl methacrylate (MMA).  相似文献   

6.
Four new chiral organolanthanide amidate complexes have been readily prepared in good yields via silylamine elimination reaction between Ln[N(SiMe3)2]3 (Ln = Sm, Y, Yb) and chiral amidate ligands, (R)-2-(mesitoylamino)-2′-methoxy-6,6′-dimethyl-1,1′-biphenyl (1H) and (R)-2-(mesitoylamino)-2′-dimethylamino-6,6′-dimethyl-1,1′-biphenyl (2H). The steric effect of the ligand coupled with the size effect of the lanthanide ion plays an important role in complex formation. For example, treatment of 1H with half equiv of Sm[N(SiMe3)2]3 gives the C2-symmetric bis-ligated amidate complex (σOMe:κO:κN-1)2SmN(SiMe3)2 (3) in 75% yield, while reaction of 1H or 2H with half equiv of Ln[N(SiMe3)2]3 (Ln = Y, Yb) affords the C1-symmetric bis-ligated amidate complexes [(κO:κN-1)(σOMe:κO:κN-1)]LnN(SiMe3)2 (Ln = Y (4), Yb (5) and the C1-symmetric mono-ligated amidate complex (σNMe2:κO:κN-2)Y[N(SiMe3)2]2 (6), respectively, in good yields. These organolanthanide amidate complexes have been characterized by various spectroscopic techniques, elemental analyses, and X-ray diffraction analyses. They are active catalysts for asymmetric hydroamination/cyclization of aminoalkenes and ring-opening polymerization of rac-lactide, affording cyclic amines in excellent conversions with good ee values and isotactic-rich polylactides, respectively.  相似文献   

7.
Reactions of neutral amino phosphine compounds HL1-3 with rare earth metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, afforded a new family of organolanthanide complexes, the molecular structures of which are strongly dependent on the ligand framework. Alkane elimination reactions between 2-(CH3NH)-C6H4P(Ph)2 (HL1) and Lu(CH2SiMe3)3(THF)2 at room temperature for 3 h generated mono(alkyl) complex (L1)2Lu(CH2SiMe3)(THF) (1). Similarly, treatment of 2-(C6H5CH2NH)-C6H4P(Ph)2 (HL2) with Lu(CH2SiMe3)3(THF)2 afforded (L2)2Lu(CH2SiMe3)(THF) (2), selectively, which gradually deproportionated to a homoleptic complex (L2)3Lu (3) at room temperature within a week. Strikingly, under the same condition, 2-(2,6-Me2C6H3NH)-C6H4P(Ph)2 (HL3) swiftly reacted with Ln(CH2SiMe3)3(THF)2 at room temperature for 3 h to yield the corresponding lanthanide bis(alkyl) complexes L3Ln(CH2SiMe3)2(THF)n (4a: Ln = Y, n = 2; 4b: Ln = Sc, n = 1; 4c: Ln = Lu, n = 1; 4d: Ln = Yb, n = 1; 4e: Ln = Tm, n = 1) in high yields. All complexes have been well defined and the molecular structures of complexes 1, 2, 3 and 4b-e were confirmed by X-ray diffraction analysis. The scandium bis(alkyl) complex activated by AlEt3 and [Ph3C][B(C6F5)4], was able to catalyze the polymerization of ethylene to afford linear polyethylene.  相似文献   

8.
[Cp2Ln(μ-OH)(THF)]2 react with 2 equiv of CyNCNCy (Cy = cyclohexyl) to form [Cp2Ln(μ-OC(NHCy)NCy)]2 (Ln = Er (1-Er), Y (1-Y)), while treatment of [Cp2Ln(μ-OH)]23-O)LnCp(THF) with CyNCNCy affords the addition/rearrangement products [Cp2Ln(μ3-O)(μ-OC(NHCy)NCy)LnCp]2 (Ln = Yb (3-Yb), Er (3-Er)). Compounds [(Cp2Ln)23-CO3)(THF)]2 (Ln = Yb (4-Yb), Er (4-Er)) can be obtained by treatment of [Cp2Ln(μ-OH)(THF)]2 with CO2 immediately followed by the reaction with the corresponding Cp3Ln. Complexes 1-4 were characterized by elemental analysis, spectroscopic properties and X-ray single crystal diffraction analysis.  相似文献   

9.
Bis(silylamino)tin dichlorides 1 [X2SnCl2 with X=N(Me3Si)2 (a), N(9-BBN)SiMe3 (b), N(tBu)SiMe3 (c), and N(SiMe2CH2)2 (d)] were prepared from the reaction of two equivalents of the respective lithium amides (Li-a-d) with tin tetrachloride, SnCl4, or from the 1:1 reaction of the respective bis(amino)stannylene with SnCl4. The compounds 1 react with two equivalents of lithium alkynides LiCCR1 to give the di(1-alkynyl)-bis(silylamino)tin compounds X2Sn(CCR1)2, 2 (R1=Me), 3 (R1=tBu), and 4 (R1=SiMe3). Problems were encountered, mainly with LiCCtBu as well as with 1b, since side reactions also led to the formation of 1-alkynyl-bis(silylamino)tin chlorides 5-7 and tri(1-alkynyl)(silylamino)tin compounds 8 and 9. 1,1-Ethylboration of compounds 2-4 led to stannoles 10, 11, and in the case of propynides, also to 1,4-stannabora-2,5-cyclohexadiene derivatives 12. The molecular structure of the stannole 11b (R1=SiMe3) was determined by X-ray analysis. The reaction of 2a and d with triallylborane afforded novel heterocycles, the 1,3-stannabora-2-ethylidene-4-cyclopentenes 14. These reactions proceed via intermolecular 1,1-allylboration, followed by an intramolecular 1,2-allylboration to give 14, and a second intramolecular 1,2-allylboration leads to the bicyclic compounds 15.  相似文献   

10.
Reaction of 3-(2-pyridylmethyl)indenyl lithium (1) with LnI2(THF)2 (Ln = Sm, Yb) in THF produced the divalent organolanthanides (C5H4NCH2C9H6)2LnII(THF) (Ln = Sm (2), Yb (3)) in high yield. 1 reacts with LnCl3 (Ln = Nd, Sm, Yb) in THF to give bis(3-(2-pyridylmethyl)indenyl) lanthanide chlorides (C5H4NCH2C9H6)2LnIIICl (Ln = Nd (4), Sm (5)) and the unexpected divalent lanthanides 3 (Ln = Yb). Complexes 2-5 show more stable in air than the non-functionalized analogues. X-ray structural analyses of 2-4 were performed. 2 and 3 belong to the high symmetrical space group (Cmcm) with the same structures, they are THF-solvated 9-coordinate monomeric in the solid state, while 4 is an unsolvated 9-coordinate monomer with a trans arrangement of both the sidearms and indenyl rings in the solid state. Additionally, 2 and 3 show moderate polymerization activities for ε-caprolactone (CL).  相似文献   

11.
Trimethylamine-trifluoroethenyl-bis(trifluoromethyl)borane [F2CCF(CF3)2B·NMe3] (1) reacts with NMe4[(CF3)2SiMe3] in THF solution to form trimethylamine-bis(trifluoromethyl)pentafluoropropenylborane [trans-CF3CFCF(CF3)2B·NMe3] (3), the fluoroborate NMe4[trans-CF3CFCF(CF3)2BF] (4), the novel borates NMe4[trans-CF3CFCFB(CF3)3] (5) and NMe4[cyclo-(CF3)2BCF2CFCF2CF3] (6).  相似文献   

12.
Metallation of (HMe2Si)(Me3Si)2CH (1) by LiMe gave the organolithium compound Li(THF)2C(SiMe3)2(SiMe2H) (2a), which exists in toluene solution as a mixture of covalent species and ion pairs [Li(THF)4][Li{C(SiMe3)2(SiMe2H)}2] (2b). Treatment of a mixture of 1 and LiMe with KOBut gave KC(SiMe3)2(SiMe2H) (3). This reacted with AlMe2Cl in hexane/THF to give Al(THF)Me2{C(SiMe3)2(Si Me2H)} (4). Treatment of (HMe2Si)(PhMe2Si)2CH (5) with LiMe in Et2O/THF gave the THF adduct [Li(THF)2C(SiMe2Ph)2(SiMe2H)] (6); in the presence of KOBut the solvent-free [K][C(SiMe2Ph)2(SiMe2H)] (7) was obtained. Crystal structure determinations showed that 6 crystallizes in a molecular lattice and 7 in an ionic lattice in which the coordination sphere of the potassium comprises phenyl groups and hydrogen atoms attached to silicon, as well as the central carbon of the bulky carbanion. Compound 7 reacted with an excess of AlMe2Cl to give [AlClMe{C(SiMe2Ph)2(SiMe2H)}]2 (8) and AlMe3. A small amount of the methoxo derivative [Al(OMe)Me{C(SiMe2Ph)2(SiMe2H)}]2 (9) was obtained as a byproduct, presumably after the accidental admission of traces of air. X-ray structural determinations showed that 8 forms halogen-bridged dimers, with the bulky ligands in the anti-configuration, and 9 forms methoxo-bridged species in which the bulky ligands are syn.  相似文献   

13.
A series of homoleptic lanthanide guanidinate (guan)3Ln · ((C2H5)2O)n (Ln=Yb, n=1 guan=(CyN)2CNiPr2, (1); Ln=Nd, n=0, guan=(CyN)2CNiPr2, (2); (iPrN)2CNiPr2, (3); (iPrN)2CN(CH2)5, (4)); (iPr=isopropyl, Cy=Cyclohexyl) were synthesized by the reaction of THF solution of lithium guanidinate with anhydrous lanthanide trichlorides in THF in 3:1 molar ratio. The molecular structures of 2 and 3 were determined to be monomeric in solid state with a six coordinate lanthanide metal ligated by six nitrogens of three guanidinate groups. All the complexes exhibited extremely high activity for the ring-opening polymerization of ε-caprolactone and the polymerization gave the polymers with high molecular weights. The different substituents at guanidino ligands have great effect on the catalytic activity. The mechanism of the polymerization was presented.  相似文献   

14.
The syntheses and structures of a series of new lanthanide complexes supported by a chelating diamide ligand N,N′-bis(trimethylsilyl)-o-phenylenediamine are described. Anhydrous LnCl3 reacts with Li2[o-(Me3SiN)2C6H4], followed by treatment of NaC5H4Me in 1:1:2 molar ratio to afford the corresponding anionic complexes: {[o-(Me3SiN)2C6H4]Ln(MeC5H4)2}{Li(DME)3} [Ln = Yb (1), Sm (2), Nd(3)] in high yield. These complexes were characterized by elemental analysis, IR and 1H NMR. The molecular structures of 1 and 2 were further determined by X-ray diffraction techniques to be an ion-pair complex composed by an anion [o-(Me3SiN)2C6H4]Ln(MeC5H4)2] and a cation [Li(DME)3]. Complexes 1-3 showed high catalytic activity for the polymerization of methyl methacrylate (MMA) at r.t., giving the syndiotactic-rich polymers with relatively narrow molecular weight distributions (Mw/Mn = 1.64-1.82).  相似文献   

15.
Treatment of (C5H4SiMe2tBu)2LnR with 1 equiv of elemental sulfur in toluene at ambient temperature gives dimeric complexes [(C5H4SiMe2tBu)2Ln(μ-SR)]2 [R = Me, Ln = Yb (1), Er (2), Dy (3), Y (4); R = nBu, Ln = Yb (5), Dy (6)]. All these complexes have been characterized by elemental analysis, IR and mass spectroscopies. The structures of complexes 1, 3, 5 and 6 are also determined through X-ray single crystal diffraction analysis, indicating that only one sulfur atom from elemental sulfur inserts into Ln–C σ-bond.  相似文献   

16.
Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en)2(dien)(η2-SbSe4)] (Ln=Ce(1a), Nd(1b)), [Ln(en)2(dien)(SbSe4)] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)(μ-η1,η2-SbSe4)] (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)(η2-SbSe4)] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe4]3− acts as a monodentate ligand mono-SbSe4, a bidentate chelating ligand η2-SbSe4 or a tridentate bridging ligand μ-η1,η2-SbSe4 to the lanthanide(III) center depending on the Ln3+ ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with Eg between 2.08 and 2.51 eV.  相似文献   

17.
Syntheses for [(diphenylphosphinoyl)methyl]-4,5-dihydrooxazole (2) and [(diarylphosphinoyl)methyl]benzoxazoles [aryl = phenyl (3), tolyl (4), 2-trifluoromethylphenyl (5) and 3,5-bis(trifluoromethyl)phenyl (6)] have been developed. Each ligand has been characterized by spectroscopic methods and single crystal X-ray diffraction analyses have been completed for 2, 3, 4 and 5. The coordination chemistry of the ligands with Nd(NO3)3 and Yb(NO3)3 has been examined and structure determinations for [Nd(2)2(NO3)3(CH3OH)], [Nd(2)2(NO3)3], [Yb(3)2(NO3)3(H2O)]·0.5(CH3OH), [Nd(3)2(NO3)3]·3(CHCl3), [Nd(4)2(NO3)3(H2O)], [Yb(4)2(NO3)3(H2O)] and [Yb(5)2(NO3)3(H2O)]·0.5(CH3CN) are reported. Depending upon conditions, the ligands act as monodentate PO or bidentate, chelating PO,N donors.  相似文献   

18.
The mono(guanidinate) lanthanide borohydride complexes of [(Me3Si)2NC(NCy)2]Ln(BH4)2(THF)2 (Ln = Yb (1), Er (2)) have been synthesized by the reactions of corresponding Ln(BH4)3(THF)3 with sodium guanidinate of [(Me3Si)2NC(NCy)2]Na in a 1:1 molar ratio in THF. They were characterized by elemental analysis, infrared spectrum and X-ray diffraction analysis. 1 and 2 have similar structures. The lanthanide ion was bonded by an η2-guanidinate ligand, two η3-BH4 ligands and two THF molecules as a distorted octahedron. The two BH4 ligands in a complex are equivalent and cis to each other. The structure of solvated sodium guanidinate of {[(Me3Si)2NC(NCy)2]Na(THF)}2 (3) was also presented. In a dimeric molecule of 3, each Na atom is bound to three nitrogen atoms from two guanidinate groups and one oxygen atom from the THF molecule. 1 and 2 displayed moderate high catalytic activity for the polymerization of methyl methacrylate. The Er complex is more active than the Yb complex.  相似文献   

19.
The yttrium chloride with the bridged bis(amidinate) L (L = Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3) LYCl(DME) (2) was synthesized and structurally characterized. Treatment of LLnCl(sol)x (Ln = Yb, sol = THF, x = 2 1; Ln = Y, sol = DME, x = 1 2) with the dilithium salt Li2L(THF)0.5 afforded the novel bimetallic lanthanide complexes supported by three ligands, Ln22-L)3 · DME (Ln = Yb 3, Y 4; DME = dimethylether), instead of the designed complex LLn(μ2-L)LnL via the ligand redistribution reaction. Complexes 3 and 4 were fully characterized including X-ray analysis and 1H NMR spectrum for 4. Reaction of LnCl3 (Ln = Yb, Y) with 2 equiv. of Li2L(THF)0.5 gave the anionic complexes [Li(DME)3][L2Ln] (Ln = Yb 5, Y 6), which were confirmed by a crystal structure determination. The further study indicated that complexes 3 and 4 can also be synthesized by reaction of LnCl3 (Ln = Yb, Y) with 1.5 equiv. of Li2L(THF)0.5 or reaction of 1 and 2 with anionic complexes 5 and 6. Complexes 3, 4, 5 and 6 were found to be high active catalysts for ring-opening polymerization of ε-caprolactone (CL).  相似文献   

20.
Reaction of (CH3C5H4)2LnCl(THF) with NaNHAr in a 1:1 molar ratio in THF afforded the amide complexes (CH3C5H4)2LnNHAr(THF) [(Ar = 2,6-Me2C6H3, Ln = Yb (I), Y (III); Ar = 2,6-iPr2C6H3, Ln = Yb (II)]. X-ray crystal structure determination revealed that complexes I-III are isostructural. The central metal in each complex coordinated to two methylcyclopentadienyl groups, one amide group and one oxygen atom from THF to form a distorted tetrahedron. Complexes I-III and a known complex (CH3C5H4)2YbNiPr2(THF) IV all can serve as the catalysts for addition of amines to nitriles to monosubstituted N-arylamidines. The activity depended on the central metals and amide groups, and the active sequence follows the trend IV ≈ III < I < II.  相似文献   

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