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1.
Electron-rich Phenyl Complexes of Transition Metals. II. Li4Co2(C6H5)4 · 4THF, Li4Co2(C6H5)4 · 3 Dioxan and Li3Co(C6H5)2(LiC6H5) · 5THF, the First Complexes with a Bis(phenyl)-cobalt(0)- and -cobalt(-I) Unity . Li2CoII(C6H5)4 · 4THF reacts spontaneously in benzene by splitting off of two phenyl radicals to a dimeric bis(phenyl) cobalt(0) complex which has been isolated as a THF and a dioxan adduct Li4Co2(C6H5)4 · 4THF and Li4Co2(C6H5)4 · 3 Dioxan, respectively. Reduction with lithiumphenyl in ether gives a phenyl cobalt(-I) complex Li4Co(C6H5)3 · 5THF containing besides σ-bonded phenyl anions lithium phenyl coordinated to cobalt in a π-complex like manner, proved by means of 13C? NMR-spectroscopy. The stabilization of the low oxidation states is explained by coordination of the lithium ions to cobalt by multiple center bonds, and for each compound a plausible structure is derived.  相似文献   

2.
Mesityl‐vanadium(III)‐phenolate Complexes: Synthesis, Structure, and Reactivity Protolysis reactions of [VMes3(THF)] with ortho‐substituted phenols (2‐iso‐propyl‐(H–IPP), 2‐tert‐butyl(H–TBP), 2,4,6‐trimethylphenol (HOMes) and 2,2′biphenol (H2–Biphen) yield the partially and fully phenolate substituted complexes [VMes(OAr)2(THF)2] (OAr = IPP ( 1 ), TBP ( 2 )), [VMes2(OMes)(THF)] ( 4 ), [V(OAr)3(THF)2] (OAr = TBP ( 3 ), OMes ( 5 )), and [V2(Biphen)3(THF)4] ( 6 ). Treatment of 6 with Li2Biphen(Et2O)4 results in formation of [{Li(OEt2)}3V(Biphen)3] ( 7 ) and with MesLi complexes [{Li(THF)2}2VMes(Biphen)2] · THF ( 8 ) and [{Li(DME)}VMes2(Biphen)] ( 9 ) are formed. Reacting [VCl3(THF)3] with LiOMes in 1 : 1 to 1 : 4 ratios yields the componds [VCl3–n(OMes)n(THF)2] (n = 1 ( 5 b ), 2 ( 5 a ), 3 ( 5 )) and [{Li(DME)2}V(OMes)4] ( 5 c ), the latter showing thermochromism due to a complexation/decomplexation equilibrium of the solvated cation. The mixed ligand mesityl phenolate complexes [{Li(DME)n}{VMes2(OAr)2}] (OAr = IPP ( 10 ), TBP ( 11 ), OMes ( 12 ) (n = 2 or 3) and [{Li(DME)2}{VMes(OMes)3}] ( 15 ) are obtained by reaction of 1 , 2 , 5 a and 5 with MesLi. With [{Li(DME)2(THF)}{VMes3(IPP)}] ( 13 ) a ligand exchange product of 10 was isolated. Addition of LiOMes to [VMes3(THF)] forming [Li(THF)4][VMes3(OMes)] ( 14 ) completes the series of [Li(solv.)x][VMes4–n(OMes)n] (n = 1 to 4) complexes which have been oxidised to their corresponding neutral [VMes4–n(OMes)n] derivatives 16 to 19 by reaction with p‐chloranile. They were investigated by epr spectroscopy. The molecular structures of 1 , 3 , 5 , 5 a , 5 a – Br , 7 , 10 and 13 have been determined by X‐ray analysis. In 1 (monoclinic, C2/c, a = 29.566(3) Å, b = 14.562(2) Å, c = 15.313(1) Å, β = 100.21(1)°, Z = 8), 3 (orthorhombic, Pbcn, a = 28.119(5) Å, b = 14.549(3) Å, c = 17.784(4) Å, β = 90.00°, Z = 8), ( 5 ) (triclinic, P1, a = 8.868(1) Å, b = 14.520(3) Å, c = 14.664(3) Å, α = 111.44(1)°, β = 96.33(1)°, γ = 102.86(1)°, Z = 2), 5 a (monoclinic, P21/c, a = 20.451(2) Å, b = 8.198(1) Å, c = 15.790(2) Å, β = 103.38(1)°, Z = 4) and 5 a – Br (monoclinic, P21/c, a = 21.264(3) Å, b = 8.242(4) Å, c = 15.950(2) Å, β = 109.14(1)°, Z = 4) the vanadium atoms are coordinated trigonal bipyramidal with the THF molecules in the axial positions. The central atom in 7 (trigonal, P3c1, a = 20.500(3) Å, b = 20.500(3) Å, c = 18.658(4) Å, Z = 6) has an octahedral environment. The three Li(OEt2)+ fragments are bound bridging the biphenolate ligands. The structures of 10 (monoclinic, P21/c, a = 16.894(3) Å, b = 12.181(2) Å, c = 25.180(3) Å, β = 91.52(1)°, Z = 4) and 13 (orthorhombic, Pna21, a = 16.152(4) Å, b = 17.293(6) Å, c = 16.530(7) Å, Z = 4) are characterised by separated ions with tetrahedrally coordinated vanadate(III) anions and the lithium cations being the centres of octahedral and trigonal bipyramidal solvent environments, respectively.  相似文献   

3.
[MoNCl3(THF)]4 – a Nitrido Complex with a Folded Mo4N4 Eight-Membered Ring Red moisture sensitive single crystals of [MoNCl3(THF)]4 ( 1 ) prepared from saturated solutions of CH2Cl2 were characterized by a crystal structure determination. Space group P 4 21c, Z = 2, lattice dimensions at –80 °C: a = b = 1291.2(1), c = 1116.3(1) pm, R = 0.0581. In 1 the molybdenum atoms are linked by nearly linear Mo≡N–Mo bridges with MoN distances of 167 and 216 pm, which corresponds with triple and single bonds. In trans position to the Mo≡N bond the THF molecule is bonded by its oxygen atom. Along the diagonal axis Mo…Mo 1 is folded with an aperture angle of 140° thus forming a butterfly structure.  相似文献   

4.
Phosphoraneiminato Complexes of Hafnium. Crystal Structures of [Hf(NPPh3)4] · 3 THF and [Hf(NPPh3)2Cl2(HNPPh3)2] The phosphoraneiminato complexes [Hf(NPPh3)4] · 3 THF ( 1 · 3 THF) and [Hf(NPPh3)2Cl2(HNPPh3)2] ( 2 ) have been prepared as colourless, moisture sensitive single crystals by reactions of hafnium tetrachloride with [CsNPPh3]4 · 2 toluene in tetrahydrofurane solutions by application of different ratios of the educts. Both complexes are characterized by IR spectroscopy and X‐ray crystal structure determinations. 1 · 3 THF: space group P 1, Z = 4, lattice dimensions at 193 K: a = 2007.6(1); b = 2064.2(1); c = 2115.9(1) pm; α = 109.193(4)°; β = 111.285(4)°; γ = 96.879(4)°; R1 = 0.0506. 1 forms monomeric molecules with tetrahedral coordination of the nitrogen‐atoms of the (NPPh3)‐groups towards the Hafnium atom. The HfN distances of 200.9 pm in average correspond with double bonds. 2 : space group P 1, Z = 4, lattice dimensions at 193 K: a = 1444.0(1); b = 1928.1(1); c = 2455.8(2) pm; α = 67.273(8)°; β = 87.445(8)°; γ = 87.082(8)°; R1 = 0.0312. 2 has a monomeric molecular structure with octahedral coordination of the hafnium atom. The chlorine atoms are in trans position to one another, whereas the nitrogen atoms of the phosphoraneiminato groups (NPPh3) are in trans position towards the nitrogen atoms ot the phosphorane imine molecules (HNPPh3). The HfN bond lengths of the (NPPh3) groups of 199.7 pm in average correspond with double bonds, whereas the HfN distances of the HNPPh3 molecules with bond lengths of 230.2 pm in average are of donor‐acceptor type.  相似文献   

5.
[Cs(toluene)3(FIn{N(SiMe3)2}3)], a Fluoroindate with Rectified Cs–F–In Axis The metalate [Cs(FIn{N(SiMe3)2}3)] has been prepared by the reaction of In[N(SiMe3)2]3 with CsF in THF: The title compound 1 can be obtained by recrystallization from toluene as colorless airsensitive needles. 1 has been characterized by NMR-, IR-, and MS-techniques as well as by an X-ray structure determination. The result of the structure analysis shows an prolated molecule with an almost linear Cs–F–In axis [174.7(1)°]. The Cs+ center is surrounded by the indate ion and three toluene molecules in a distorted tetrahedral fashion.  相似文献   

6.
Syntheses and Crystal Structures of the Nitrido‐chloro‐molybdates [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 and [Li(12‐Crown‐4)(NMoCl4)]2 · 2 CH2Cl2 Both the title compounds as well as [Li(12‐crown‐4)2]+MoNCl4 were made from MoNCl3 and the chlorides MgCl2 and LiCl, respectively, in dichloromethane suspensions in the presence of tetrahydrofuran and 12‐crown‐4, respectively. They form orange‐red moisture‐sensitive crystals, which were characterized by their IR spectra and partly by crystal structure analyses. [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 ( 1 ): space group C2/m, Z = 2, lattice dimensions at –50 °C: a = 1736.6(1), b = 1194.8(1), c = 1293.5(2) pm; β = 90.87(1)°; R1 = 0.037. In 1 the magnesium ion is coordinated octahedrally by the oxygen atoms of the four THF molecules and in trans‐position by the nitrogen atoms of the two [N≡MoCl4(THF)] ions. [Li(12‐crown‐4)(NMoCl4)]2 · 2 CH2Cl2 ( 2 ): space group P 1, Z = 1, lattice dimensions at –70 °C: a = 930.4(1), b = 957.9(1), c = 1264.6(1) pm; α = 68.91(1)°, β = 81.38(1)°, γ = 63.84(1)°; R1 = 0.0643. 2 forms a centrosymmetric ion ensemble in the dimeric cation of which, i. e. [Li(12‐crown‐4)]22+, the lithium ions on the one hand are connected to the four oxygen atoms each of the crown ether molecules in a way not yet known; and in addition, each of the lithium ions enters into a intermolecular Li–O bond with neighboring crown ether molecules under formation of a Li2O2 four‐membered ring. The two N≡MoCl4 counterions are loosely coordinated to one oxygen atom each of the crown ether molecules with Mo–O distances of 320.2 pm.  相似文献   

7.
Synthesis and Structure of Complexes with Nitrido Bridges between Rhenium and Zinc The reaction of [ReNCl2(PMePh)3] with ZnX2 (X = Cl, Br) in CH2Cl2 yields the tetranuclear complexes [(Me2PhP)3X2Re≡N–ZnX2]2. In case of the reaction with ZnBr2 an exchange of the halogen atoms coordinated to the Re atom occurs. [(Me2PhP)3Cl2Re≡N–ZnCl2]2 ( 1 ) crystallizes with one centrosymmetric tetranuclear complex in the triclinic unit cell. [(Me2PhP)3Br2Re≡N–ZnBr2]2 ( 2 ) forms triclinic crystals with the composition 2 · 2 CH2Cl2. The centrosymmetric tetranuclear complexes exhibit analogous structures. Two complexes [ReNX2(PMe2Ph)3] coordinate with the terminal nitrido ligands the Zn atoms of a central unit XZn(μ-X)2ZnX. The resulting linear nitrido bridges Re≡N–Zn (Re–N–Zn = 178.4° ( 1 ) und 178.0° ( 2 )) are asymmetric with distances Re–N = 170 pm and Zn–N = 199 pm for 1 , and Re–N = 167 pm as well as Zn–N = 201 pm for 2 . The reaction of [ReNCl2(PMe2Ph)3] with ZnI2 in CH2Cl2 presumably first affords [(Me2PhP)3ClIRe≡N–ZnI2]2, which, however, in the course of crystallization decomposes to yield [(Me2PhP)3ClIRe≡N–ZnI2(OPMe2Ph)] ( 3 ). Of the two Cl atoms originally coordinated at the Re atom the one in cis position to the nitrido ligand is substituted by iodine. 3 forms monoclinic crystals with the space group P21/n. The distances in the linear nitrido bridge (Re–N–Zn = 171.5°) are Re–N = 167.9 pm and Zn–N = 204.9 pm. By the reaction of [ReNCl2(PMe2Ph)3] with ZnX2 (X = Cl, I) in THF the dinuclear complexes [(Me2PhP)3Cl2Re≡N–ZnCl2(THF)] ( 4 ) and [(Me2PhP)3ClIRe≡N–ZnI2(THF)] ( 5 ) are obtained. They crystallize isotypically as 4 · THF or 5 · THF in the triclinic space group P1. Their nitrido bridges have the following parameters: Re–N–Zn = 175.2°, Re–N = 167.7 pm, and Zn–N = 202.1 pm for 4 , resp. Re–N–Zn = 174.7°, Re–N = 168.3 pm, and Zn–N = 201.2 pm for 5 .  相似文献   

8.
Only a few cyclooctatetraene dianion (COT) π‐complexes of lanthanides have been crystallographically characterized. This first single‐crystal X‐ray diffraction characterization of a scandium(III) COT chloride complex, namely di‐μ‐chlorido‐bis[(η8‐cyclooctatetraene)(tetrahydrofuran‐κO )scandium(III)], [Sc2(C8H8)2Cl2(C4H8O)2] or [Sc(COT)Cl(THF)]2 (THF is tetrahydrofuran), (1), reveals a dimeric molecular structure with symmetric chloride bridges [average Sc—Cl = 2.5972 (7) Å] and a η8‐bound COT ligand. The COT ring is planar, with an average C—C bond length of 1.399 (3) Å. The Sc—C bond lengths range from 2.417 (2) to 2.438 (2) Å [average 2.427 (2) Å]. Direct comparison of (1) with the known lanthanide (Ln) analogues (La, Ce, Pr, Nd, and Sm) illustrates the effect of metal‐ion (M ) size on molecular structure. Overall, the M —Cl, M —O, and M —C bond lengths in (1) are the shortest in the series. In addition, only one THF molecule completes the coordination environment of the small ScIII ion, in contrast to the previously reported dinuclear Ln–COT–Cl complexes, which all have two bound THF molecules per metal atom.  相似文献   

9.
Mesityl Oxo Molybdenum and Tungsten Compounds. III. Reactions of WOCl4 with Mesityl Grignard Reagent – X-Ray Crystal Structures of [ClMg(THF)4{OWCl4(THF)}], [Mg(THF)4{OWCl4(THF)}2], and WOMes3(THF)2 The reaction of WOCl4 with MesMgBr (1 : 1) in tetrahydrofuran (THF) proceeds via reduction to tungsten(V), which can be isolated as [MgX(THF)4][WOCl4(THF)] ( 2 ) and by elimination of MgX2 in form of [Mg(THF)4{OWCl4(THF)}2] ( 3 ). The reaction of WOCl4 with MesMgBr in the molar ratio 1 : 4 yields after reduction [WOMes3(THF)] · THF ( 4 ). All complexes are characterized by X-ray structure analyses. In 2 and 3 [WOCl4(THF)] anions are linked via their oxo ligands to the magnesium ions. 4 has a distorted trigonal bipyramidal coordination sphere.  相似文献   

10.
Treatment of the trigonal-bipyramidal ruthenium(IV)–thiolate complex, [Ru(SMes)4(MeCN)] (Mes = 2,4,6-trimethylphenyl, 1), with an anhydrous diethyl ether solution of hydrogen chloride in THF afforded [Ru(SMes)3Cl(MeCN)] (2), whereas interaction of 1 with [Et4N]Cl in THF gave an anionic ruthenium(IV)–thiolate complex, [Et4N][Ru(SMes)4Cl] (3). Reaction of 1 with one equivalent of substituted pyridines in dichloromethane gave the corresponding pyridine-coordinated ruthenium(IV)–thiolate complexes, [Ru(SMes)4(R-py)] (R = 4-Et, 4; 4-tBu, 5; 3,5-Me2, 6), while reaction of 1 with 0.5 equiv. of 4,4’-bipy (4,4’-bipy = 4,4’-bipyridine) in dichloromethane resulted in the formation of a dinuclear ruthenium(IV)–thiolate complex [{Ru(SMes)4}2(μ-4,4’-bipy)] (7). Complexes 27 have been spectroscopically characterized along with their electrochemical analyses, and their structures have been determined by single-crystal X-ray diffraction.  相似文献   

11.
Reaction of C(NMe2)4 with Ni(CO)4 – Syntheses and Structures of [C(NMe2)3][(CO)3NiC(O)NMe2], [C(NMe2)3]2[Ni5(CO)12], and [C(NMe2)3]3[Ni6(CO)12][O2CNMe2] The reaction of C(NMe2)4 with Ni(CO)4 in THF produces the carbamoyl complex [C(NMe2)3][(CO)3NiC(O)NMe2] ( 1 ); side products are the purple cluster compound [C(NMe2)3]2[Ni5(CO)12] · THF ( 2 · THF) and the red cocristallization product [C(NMe2)3]3[Ni6(CO)12][O2CNMe2] ( 3 ). All compounds were studied by X‐ray diffraction analyses. The cations of 3 are all disordered but not those of 1 and 2 . The unit cell of 1 contains two crystallographically independent anions (I and II) which differ in the dihedral angle between the plane of the carbamoyl ligand and the plane defined by the atoms CCarbamoyl–Ni–CO amounting 0° in the anion I and 18° in the anion II.  相似文献   

12.
《Mendeleev Communications》2021,31(5):628-630
Solid phase thermolysis of pivalate complex [Fe3O(Piv)6(HPiv)3]Piv generates the [Fe3O(Piv)6]+ complex cation due to a deficiency of ligands in the coordination sphere of the metal ions. Crystallization of [Fe3O(Piv)6]+ from THF–EtOH leads to the heteroleptic complex [Fe3O(Piv)6(THF)(EtOH)(OH)] · 0.5 THF · 0.5 H2O in 69% yield, while the reaction of [Fe3O(Piv)6]+ with AgNO3 in toluene results in the complex [Fe4Ag4O2(Piv)12] · 2 PhMe with a rare combination of FeIII and AgI atoms. Crystal structures of the two new complexes have been established.  相似文献   

13.
The Reactions of Europium and Yttrium with N‐Iodinetriphenylphosphoraneimine. Crystal Structures of [EuI2(DME)3], [Eu2I(NPPh3)5(DME)] and [Y2I(NPPh3)4(THF)4]+I3 When treated with ultrasound, the reaction of europium metal with INPPh3 in 1,2‐dimethoxyethane (DME) leads to the complexes [EuI2(DME)3] ( 1 ) and [Eu2I(NPPh3)5(DME)] ( 2 ) which are separated from each other by fractional crystallization. On the other hand, the reaction of yttrium metal with INPPh3 under similar conditions in THF gives the ionic phosphoraneiminato complex [Y2I(NPPh3)4(THF)4]+I3 ( 3 ). All complexes are characterized by crystal structure determinations. 1 : Space group P21, Z = 2, lattice dimensions at 188 K: a = 848.9(1); b = 1059.4(1); c = 1227.9(1) pm; β = 93.793(6)°; R = 0.0246. In the molecular structure of 1 the europium atom is eightfold coordinated with a bond angle I–Eu–I of 158.51°. 2 · 2 DME: Space group P1, Z = 2, lattice dimensions at 193 K: a = 1405.5(1); b = 1652.2(2); c = 2203.7(2) pm; α = 89.404(11)°; β = 72.958(11)°; γ = 78.657(11)°; R = 0.0391. In 2 the europium atoms are linked by the μ‐N‐atoms of two (NPPh3) groups to form a planar Eu2N2 four‐membered ring. One of the Eu atoms is terminally coordinated by the N atoms of two (NPPh3) groups, thus achieving a distorted tetrahedral surrounding. The second Eu atom is coordinated by the N atom of one (NPPh3) group, by the terminally bounded iodine atom and by the oxygen atoms of the DME chelate, thus achieving a distorted octahedral surrounding. 3 · 61/2 THF: Space group P1, Z = 2, lattice dimensions at 103 K: a = 1739.7(2); b = 1770.1(2); c = 2153.8(3) pm; α = 74.929(15)°; β = 84.223(14)°; γ = 64.612(12)°; R = 0.0638. In the cation [Y2I(NPPh3)4(THF)4]+ of 3 the yttrium atoms are linked by the μ‐N atoms of two (NPPh3) groups as well as by the μ‐I atom. One (NPPh3) ligand and two THF molecules complete the distorted octahedral coordination at each yttrium atom.  相似文献   

14.
Group selectivity in the allylation of mixed (n‐butyl)(phenyl)zinc reagent can be controlled by changing reaction parameters. CuCN‐catalyzed allylation in tetrahydrofuran (THF)–hexamethylphosphoric triamide is n‐butyl selective and also γ‐selective in the presence of MgCl2, whereas CuI‐catalyzed allylation in THF in the presence of n‐Bu3P takes place with a n‐butyl transfer:phenyl transfer ratio of 23:77 and an α:γ transfer ratio of phenyl of 76:24. NiCl2(Ph3P)2‐catalyzed allylation in the presence of LiCl is phenyl selective with an α:γ ratio of 65:35. The reaction of methyl‐ or n‐butyl(aryl)zinc reagents with an allylic electrophile in THF at room temperature in the presence of NiCl2(Ph3P)2 catalyst and LiCl as an additive provides an atom‐economic alternative to aryl–allyl coupling using diarylzincs. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

15.
Syntheses and Crystal Structures of the Rare-Earth Complexes [LaI2(THF)5]+I3?, [SmCl3(THF)4], [ErCl2(THF)5]+ [ErCl4(THF)2]?, [ErCl3(DME)2], and [Na(18-Crown-6)(THF)2]+[YbBr4(THF)2]? [LaI2(THF)5]+I3? ( 1 ) is obtained as red crystals from lanthanum powder and 1,2-diiodoethane in THF on exposure to light. Space group Pbcn, Z = 4, lattice dimensions at ?83°C: a = 1264.9, b = 2218.9, c = 1199.1 pm, R = 0.031. The lanthanum atom of the cation of 1 is coordinated with iodine atoms in the axial positions in a pentagonal-bipyramidal way. [SmCl3(THF)4] ( 2 ) originates as colourless crystals on heating SmCl3 with excess THF in the presence of Me3SiNPEt3. Space group P21/c, Z = 8, lattice dimensions at ?50°C: a = 3092.7, b = 826.2, c = 1758.3 pm, β = 93.85°, R = 0.054. Just like the known sample that crystallizes within the space group F2dd, 2 forms monomeric molecules in which the samarium atom is coordinated with two chlorine atoms in the axial positions in a distorted pentagonal-bipyramidal way. [ErCl2(THF)5]+[ErCl4(THF)2]? ( 3 ). Pale pink single crystals of 3 were prepared according to the described method by reaction of erbium powder with trimethylchlorosilane and methanol in THF. Space group C2/c, Z = 4, lattice dimensions at ?50°C: a = 1246.3, b = 1145.7, c = 2726.0 pm, β = 91.293°, R = 0.036. The erbium atom of the cation of 3 has a pentagonal-bipyramidal coordination with the chlorine atoms in the axial positions. Within the anion the THF molecules are in trans-arrangement of the octahedrally coordinated erbium atom. [ErC13(DME)2] ( 4 ) originates as pink single crystals from 3 with excess boiling 1,2-dimethoxyethane. Space group P21/c, Z = 4, lattice dimensions at ?50°C: a = 1137.2, b = 886.5, c = 1561.1 pm, β = 104.746°, R = 0.032. 4 forms monomeric molecules in which the erbium atom has a pentagonal-bipyramidal surrounding with two chlorine atoms in the axial positions. [Na(18-Krone-6)(THF)2]+ [YbBr4(THF)2]? ( 5 ) is formed as by-product by the reaction of YbBr3 with NaN(SiMe3)2 in THF in the presence-of 18-crown-6 forming colourless crystals. Space group P1 , Z = 1, lattice dimensions at ?70°C: a = 934.6, b = 988.9, c = 1208.0 pm, α = 73.82°, β = 72.98°, γ = 76.89°, R = 0.029. 5 contains isolated [YbBr4(THF)2]?ions, in which the THF molecules are arranged in trans-position.  相似文献   

16.
The quasi‐living copolymerization of ethylene with propylene was achieved by using N‐heterocyclic carbene (NHC) ligated vanadium complex ( V3 , VOCl3[1,3‐(2,6‐iPr2C6H3)2(NCH?)2C:]) due to the stabilization of active center by the introduction of bulky and electron rich NHC ligand with bulky isopropyl substituents at the ortho positions of the phenyl rings. The weight‐average molecular weight (Mw) of the resulting copolymer increases linearly with its weight in 20 min. The ultra‐high‐molecular‐weight (UHMW) ethylene‐propylene copolymer (Mw = 1612 kg mol?1) can be synthesized with V3 /Et3Al2Cl3 catalytic system. The novel complex V4′ (VCl3[1,3‐(2,4,6‐Me3C6H2)2(NCH?)2C:]·2THF) was constructed by the introduction of two coordinated tetrahydrofuran molecules and decrease in steric hindrance at the ortho positions of phenyl rings. The UHMW ethylene‐propylene copolymer (Mw = 1167 kg mol?1) can also be synthesized by using V4′ /Et3Al2Cl3 catalytic system. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 553–561  相似文献   

17.
Crystal Structure of the Isothiocyanato Complex [Ph3PNH2(OEt2)][Sm(NCS)4(DME)2] Colourless single crystals of [Ph3PNH2(OEt2)][Sm(NCS)4(DME)2] ( 1 ) have been obtained besides of Ph3PS from the reaction of the homoleptic phosphorane iminato complex [Sm(NPPh3)3]2 with carbon disulfide in THF solution, followed by recrystallisation from DME/Et2O. According to the crystal structure analysis 1 consists of [Ph3PNH2]+ cations with the diethylether molecule forming a N–H…O hydrogen bridge, and anions [Sm(NCS)4(DME)2]. Sm3+ realizes coordination number eight by four nitrogen atoms of the isothiocyanato ions and by four oxygen atoms of the DME chelates. 1 : Space group P 1, Z = 4, lattice dimensions at 193 K: a = 919.0(1), b = 1965.2(2), c = 2401.3(2) pm, α = 96.748(11)°, β = 94.827(10)°, γ = 91.720(11)°, R = 0.029.  相似文献   

18.
The Reaction of Ytterbium with N‐iodo‐triphenylphosphaneimine. Crystal Structures of [Yb2I(THF)2(NPPh3)4] · 2 THF, [YbI2(HNPPh3)(DME)2], and [{YbI2(DME)2}2(μ‐DME)] When treated with ultrasound, the reaction of ytterbium powder with INPPh3 in tetrahydrofuran leads to [YbI2(THF)4] and to the mixed‐valence phosphoraneiminato complex [Yb2I(THF)2(NPPh3)4] · 2 THF ( 1 ), which forms red single‐crystals. In the analogous reaction in 1,2‐dimethoxyethane (DME) only the ytterbium(II) iodide solvates [YbI2(HNPPh3)(DME)2] ( 2 ) and [{YbI2(DME)2}2 · (μ‐DME)] ( 3 ) can be isolated, which form yellow single crystals. All compounds were characterized by crystal structure analyses. 1 : Space group P1, Z = 2, lattice dimensions at –80 °C: a = 1337.6(5), b = 1389.6(5), c = 2244.2(17) pm; α = 86.11(7)°, β = 88.06(7)°, γ = 88.63(4)°; R = 0.0759. In 1 the two ytterbium atoms are connected via the N atoms of two phosphoraneiminato groups (NPPh3) to form a planar Yb2N2 four‐membered ring. The structure can also be described as an ion pair consisting of [YbI(THF)2]+ and [Yb(NPPh3)4]. 2 : Space group P21, Z = 2, lattice dimensions at –80 °C: a = 811.9(1), b = 1114.0(1), c = 1741.3(1) pm; β = 95.458(5)°; R = 0.0246. 2 forms molecules in which the ytterbium atom is coordinated in a pentagonal‐bipyramidal fashion with the iodine atoms in the axial positions. The O atoms of the two DME‐chelates and the N atom of the phosphaneimine ligand HNPPh3 are in the equatorial positions. 3 : Space group P1, Z = 2, lattice dimensions at –70 °C: a = 817.5(1), b = 1047.7(1), c = 1115.5(2) pm; α = 90.179(10)°, β = 97.543(15)°, γ = 91.087(12)°; R = 0.0317. 3 has a dimeric molecular structure, in which the two fragments {YbI2(DME)2} are connected centrosymmetrically via a μ‐DME bridge. As in 2 , the ytterbium atoms are coordinated in a pentagonal‐bipyramidal fashion with the iodine atoms in the axial positions, as well as with the two DME chelates and with one O atom each of the μ‐DME ligand in the equatorial positions.  相似文献   

19.
A single molecular heterobimetallic complex, [Co2Ti(μ3‐O)(TFA)6(THF)3] (1) [TFA = trifluoroacetate, THF = tetrahydrofuran], was synthesized, structurally and spectroscopically characterized and implemented as a single‐source precursor for the preparation of CoTiO3–CoO composite thin films by aerosol‐assisted chemical vapour deposition (AACVD). The precursor complex was prepared by interaction of Co(OAc)2.4H2O [OAc = (CH3COO?)] with Ti(iso‐propoxide)4 in the presence of trifluoroacetic acid in THF, and was analysed by melting point, CHN, FT‐IR, single‐crystal X‐ray diffraction and thermogravimetric analysis. The precursor complex thermally decomposed at 480 °C to give a residual mass corresponding to a CoTiO3–CoO composite material. Good‐quality crystalline CoTiO3–CoO composite thin films deposited at 500 °C by AACVD and characterized through powder X‐ray diffraction and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy show that the crystallites have a rose‐flower‐like morphology with an average petal size in the range of 2–6 µm. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

20.
Reactions of MoNCl3 and WNCl3 with Elemental Fluorine. Crystal Structures of [MoO2F2(THF)2] and [WF4(NCl)(CH3CN)] The nitrido chlorides MoNCl3 and WNCl3 as well as WCl4(NCl) react with elemental fluorine forming the N-chloro imido complexes MoF4(NCl) and WF4(NCl), which were characterized by IR spectroscopy. With tetrahydrofurane MoF4(NCl) reacts to give [MoF4(NCl)(THF)], which in THF solution slowly converts into [MoO2F2(THF)2]. From WF4(NCl) with acetonitrile the complex [WF4(NCl)(CH3CN)] is obtained. Both donor acceptor complexes were characterized by crystal structure determinations. [MoO2F2(THF)2] : Space group P21/n, Z = 4, structure solution with 1823 unique reflections, R = 0.033 for reflections with I > 2σ(I). Lattice dimensions at ?40°C: a = 636.2, b = 1119.5, c = 1625.2 pm; β = 93.92(1)º. The compound has a monomeric molecular structure with the fluorine atoms in trans-position to one another and with the oxygen atoms of the THF molecules in trans to the oxo ligands. [WF4(NCl)(CH3CN)] : Space group P21/m, Z = 2, structure solution with 1119 unique reflections, R = 0.038 for reflections with I > 2σ(I). Lattice dimensions at 20°C: a = 511.7, b = 714.9, c = 1002.5 pm; β = 102.59(10)º. The compound has a monomeric molecular structure in which the nitrogen atom of the acetonitrile molecule coordinates in trans-position to the N-chloro imido group W?N? Cl. The structural parameters of this group are WN = 172.2 pm, NCl = 161.1 pm, WNCl = 178.6º.  相似文献   

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