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1.
The crystal structure of the title compound, [Ag(C18H15P)4]2[Sn2(CH3)4(CF3CO2)6], consists of discrete tetrahedral cations and trans‐C2SnO4 octahedral dianions [C—Sn—C = 154.6 (2)°]. The dianion lies about a center of inversion and the two Sn atoms are linked unevenly by the carboxyl­ate unit [Sn—O = 2.291 (3) Å and SnO = 2.818 (3) Å].  相似文献   

2.
Compound [Zn(CF3CO2)2(Bpp)2], where Bpp is 1,3-bis(4-pyridyl)propane, was synthesized and its structure and luminescent properties were determined. Crystals are monoclinic, space group C2/c, a = 21.261(1) Å, b = 17.642(1) Å, c = 18.632(1) Å, β = 115.85(1)°, V = 6289.3(6) Å3, ρcalcd = 1.453 g/cm3, Z = 8. The structure comprises 2D neutral layers of conjugated multiunit rings composed of four Zn2+ ions united by four bridging Bpp ligands. Each of two crystallographically nonequivalent Zn atoms is coordinated at the octahedra apices to four nitrogen atoms of two Bpp ligands and two O(CF3CO2) atoms. Trifluoroacetate anions are coordinated to Zn2+ ions in monodentate manner. The compound exhibits photoluminescence in solid state.  相似文献   

3.
Reactions of lanthanoid trichlorides with sodium cyclopentylcyclopentadienyl in THFafford bis(cyclopentylcyclopentadienyl) lanthanoid chloride complexes (C_5H_9C_5H_4)_2LnCl(THF)_n (Ln=Nd, Sm, n=1; Ln= Er, Yb, n= 0). The compound [CP'_2SmCl(THF)]_2 (2) (Cp' =cyclopentylcy-clopentadienyl) crystallizes from mixed solvent of hexane and THF in monoclinic space group P_2_1/cwith a = 11.583 (3), b = 23.019(6), c = 8.227 (2), β= 90.26 (2)°, V= 2194 (1)~3, D_c= 1.59 g/cm~3.μ= 28.6 cm~(-1), F(000) = 1060, Z= 2 (dimers). Its crystal molecule is a dimer with a crystallographicsymmetry center. The central metal atom Sm is coordinated to two Cp' rings, two bridging chlorineatoms and one THF forming a distorted trigonal bipyramid. The crystal of [Cp'_2ErCl]_2 (3) belongs tothe triclinic space group P with a = 11.264 (2), b= 13.296(5), c = 14.296(6), a = 96.99 (3), β=112.47(2), γ= 102.78(2)°, V= 1865(1)~3, D_c= 1.67 g /cm~3, μ= 48.0 cm~(-1), F(000) = 924, Z = 2 (dimers).The molecule is a dimer consisting of two Cp'_2 ErCl species bridged by two Cl atoms. The centralmetal atom Er is coordinated to two Cp' rings and two bridging chlorine atoms forming a pseudo-tetrahedron. All these complexes are soluble in THF, DME, Et_2O, toluene and hexane.  相似文献   

4.
Bis‐trimethylamine‐ethynyl‐di‐bis(trifluoromethyl)borane [Me3N(CF3)2BCCB(CF3)2NMe3] ( 1 ) has been prepared from trimethylamine‐ethynyl‐bis(trifluoromethyl)borane, [HCCB(CF3)2NMe3], and dimethylamino‐bis(trifluoromethyl)borane, (CF3)2BNMe2. The structure of 1 has been determined by x‐ray crystallography. In the solid state the molecule possesses crystallographic Ci symmetry. The acetylenic attachment to the boron atom is characterized by a short B–C bond length of 1.565(4) Å and an essentially linear B–C–C′ bond angle of 178.1(4)°.  相似文献   

5.
Syntheses and NMR Spectroscopic Ivestigations of Salts containing the Novel Anions [PtXn(CF3)6‐n]2— (n = 0 ‐ 5, X = F, OH, Cl, CN) and Crystal Structure of K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O The first syntheses of trifluoromethyl‐complexes of platinum through fluorination of cyanoplatinates are reported. The fluorination of tetracyanoplatinates(II), K2[Pt(CN)4], and hexacyanoplatinates(IV), K2[Pt(CN)6], with ClF in anhydrous HF leads after working up of the products to K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O. The structure of the salt is determined by a X‐ray structure analysis, P21/c (Nr. 14), a = 11.391(2), b = 11.565(2), c = 13.391(3)Å, β = 90.32(3)°, Z = 4, R1 = 0.0326 (I > 2σ(I)). The reaction of [Bu4N]2[Pt(CN)4] with ClF in CH2Cl2 generates mainly cis‐[Bu4N]2[PtCl2(CF3)4] and fac‐[Bu4N]2[PtCl3(CF3)3], but in contrast that of [Bu4N]2[Pt(CN)6] with ClF in CH2Cl2 results cis‐[Bu4N]2[PtX2(CF3)4], [Bu4N]2[PtX(CF3)5] (X = F, Cl) and [Bu4N]2[Pt(CF3)6]. In the products [Bu4N]2[PtXn(CF3)6‐n] (X = F, Cl, n = 0—3) it is possibel to exchange the fluoro‐ligands into chloro‐ and cyano‐ligands by treatment with (CH3)3SiCl und (CH3)3SiCN at 50 °C. With continuing warming the trifluoromethyl‐ligands are exchanged by chloro‐ and cyano‐ligands, while as intermediates CF2Cl and CF2CN ligands are formed. The identity of the new trifluoromethyl‐platinates is proved by 195Pt‐ and 19F‐NMR‐spectroscopy.  相似文献   

6.
Alcoholysis of [Fe2(OtBu)6] as a Simple Route to New Iron(III)‐Alkoxo Compounds: Synthesis and Crystal Structures of [Fe2(OtAmyl)6], [Fe5OCl(OiPr)12], [Fe5O(OiPr)13], [Fe5O(OiBu)13], [Fe5O(OCH2CF3)13], [Fe5O(OnPr)13], and [Fe9O3(OnPr)21] · nPrOH New alkoxo‐iron compounds can be synthesized easily by alcoholysis of [Fe2(OtBu)6] ( 1 ). Due to different bulkyness of the alcohols used, three different structure types are formed: [Fe2(OR)6], [Fe5O(OR)13] and [Fe9O3(OR)21] · ROH. We report synthesis and crystal structures of the compounds [Fe5OCl(OiPr)12] ( 2 ), [Fe2(OtAmyl)6] ( 3 ), [Fe5O(OiPr)13] ( 4 ), [Fe5O(OiBu)13] ( 5 ), [Fe5O(OCH2CF3)13] ( 6 ), [Fe9O3(OnPr)21] · nPrOH ( 7 ) and [Fe5O(OnPr)13] ( 8 ). Crystallographic Data: 2 , tetragonal, P 4/n, a = 16.070(5) Å, c = 9.831(5) Å, V = 2539(2) Å3, Z = 2, dc = 1.360 gcm?3, R1 = 0.0636; 3 , monoclinic, P 21/c, a = 10.591(5) Å, b = 10.654(4) Å, c = 16.740(7) Å, β = 104.87(2)°, V = 1826(2) Å3, Z = 2, dc = 1.154 gcm?3, R1 = 0.0756; 4 , triclinic, , a = 20.640(3) Å, b = 21.383(3) Å, c = 21.537(3) Å, α = 82.37(1)°, β = 73.15(1)°, γ = 61.75(1)°, V = 8013(2) Å3, Z = 6, dc = 1.322 gcm?3, R1 = 0.0412; 5 , tetragonal, P 4cc, a = 13.612(5) Å, c = 36.853(5) Å, V = 6828(4) Å3, Z = 4, dc = 1.079 gcm?3, R1 = 0.0609; 6 , triclinic, , a = 12.039(2) Å, b = 12.673(3) Å, c = 19.600(4) Å, α = 93.60(1)°, β = 97.02(1)°, γ = 117.83(1)°, V = 2600(2) Å3, Z = 2, dc = 2.022 gcm?3, R1 = 0.0585; 7 , triclinic, , a = 12.989(3) Å, b = 16.750(4) Å, c = 21.644(5) Å, α = 84.69(1)°, β = 86.20(1)°, γ = 77.68(1)°, V = 4576(2) Å3, Z = 2, dc = 1.344 gcm?3, R1 = 0.0778; 8 , triclinic, , a = 12.597(5) Å, b = 12.764(5) Å, c = 16.727(7) Å, α = 91.94(1)°, β = 95.61(1)°, γ = 93.24(2)°, V = 2670(2) Å3, Z = 2, dc = 1.323 gcm?3, R1 = 0.0594.  相似文献   

7.
Abstract

The first structural data on a pentamethylcyclopentadienyl complex ofthulium, [(C5Me5)2Tm(μ3-C1)2K(THF)]n,1, are reported. TmCl3 reacts with 2 equivalents ofKC5Me5 in THF to form 1 in <80% yield. 1 crystallizes from THF/hexanes in thespace group Cc with a = 11.1491(13) Å, b= 28.107(2) Å, c = 8.5921(8) Å, β= 102.485(8)°, V = 2628.8(4) Å3, and Dcalcd = 1.570 Mg/m3 for Z= 4. Least-squares refinement of the model based on 3114reflections (F2 > 3.0 [sgrave] (F2))converged to a final RF = 1.9%. Thepolymeric structure of 1 is generated by triply bridgingchlorides, each of which is connected to one(C5Me5)2Tm bentmetallocene unit and two K(THF) moieties in a T-shaped geometryaround the chloride.  相似文献   

8.
Monomeric and Dimeric Oxovanadium(IV)-phenolate Complexes: Synthesis, Structure, and Reaction with a Reducing and Arylation Agent Reaction of [OVCl2(THF)2] with LiOMes yields dimeric [Li(Et2O)2OVCl2(μ-OMes)]2 ( 1 ) which can be converted with excess LiOMes to the substitution product [Li(THF)2OV(OMes)3(THF)] ( 2 ). Treatment of ( 1 ) with LiMes results in the formation of complexes [Li(THF)3OVMes3] ( 3 ) and [Li(THF)3OVMes2(OMes)] ( 4 ). Complex [{Li(THF)2OV(OMes)2(μ-OH)}2 · 2 THF] ( 6 ) has been isolated as a by-product of an unknown reaction of [OV(OMes)3] and Li. The structures of 1 , 2 , 3 , and 6 have been determined by X-ray analysis. In 1 (monoclinic, P21/c, a = 9.522(1) Å, b = 19.777(2) Å, c = 12.311(1) Å, β = 104.45(1)°, Z = 2) the vanadium atoms which are bridged by the phenolate ligands show a square-pyramidal coordination sphere. The central atom in 2 (monoclinic, P21/c, a = 17.755(2) Å, b = 11.629(1) Å, c = 20.956(3) Å, β = 113.98(1)°, Z = 4) has a bipyramidal environment which is realized by coordination of a THF donor molecule. The (THF)2Li fragment is bound via bridging phenolate ligands. The structure of 3 (orthorhombic, P212121, a = 15.465(2) Å, b = 15.456(2) Å, c = 15.469(2) Å, Z = 4) is built up by two tetrahedrons linked by the oxo atom. Dimeric 6 (triclinic, P1, a = 10.780(4) Å, b = 11.428(2) Å, c = 13.734(3) Å, α = 77.24(2)°, β = 84.79(2)°, γ = 74.35(2)°, Z = 1) has a structure similar to 1 . The vanadium atoms are bridged by two OH groups while phenolate ligands link the lithium cations with the vanadium atoms.  相似文献   

9.
The [Ag(CF3CO2)(2-Me-Pyz)] complex (where 2-Me-Pyz is 2-methylpyrazine) was synthesized and its structure was determined. The crystals are monoclinic, space group P21/n, a = 12.440(2) Å, b = 2.605(3) Å, c = 12.646(3) Å, β = 95.95(3)°, V = 1972.3(7) Å3, ρ = 2.122 g/cm3, Z = 8. The structure consists of the polymer zigzag chains of [Ag(C5H6N2)] ? united into a three-dimensional framework through (CF3CO2)? anions.  相似文献   

10.
The title reaction gave three known compounds (2, 3 and 4) and two new compounds, CH3SCH2(CF2)2H (5) and I(CF2)2O(CF2)2SO3S+(CH3)3 (6). The structure of 6 was confirmed by X-ray diffraction analysis. The crystals of 6 belong to monoclinic space group P21/C with a = 9.399, b = 15.651, c=10.934Å, β = 94.80° and z = 4. The structure was solved by heavy-atom method and refined by block-diagonal matrix least-squares procedure to a final R of 0.054 for 1999 independent observed reflexions. The S C bonds around the sulphur atom in trimethylsulphonium are pyramidal with the bond lengths of 1.814 Å, 1.800Å and 1.818 Å and the bond angles C-S-C of 101.06°, 101.52° and 102.53°. The distances of the sulphur atom in trimethylsulphonium to three oxygen atoms in the sulphonate radical are 3.79 Å, 3.64 Å and 3.34 Å respectively. These distances are out of the range of the normal S-O bond length. The structure consists of trimethylsulphonium cations and 5-iodo-3-oxaoctafluoropentane-sulphonate anions.  相似文献   

11.
The molecular structures of C2F5H and C2H5F have been studied using gas-phase electron diffraction data collected on the Balzers KDG2 instrument. The following values for the main independent geometrical parameters were obtained (ra values with e.s.d. in parentheses): in C2F5H, C-C = 1.525(4) Å, C-F(CHF2) = 1.347 Å, C-F(CF3) = 1.327 Å [C-F(av.) = 1.335(2) Å], ∠CCF(av.) = 110.0(2)°; in C2H5F, C-C = 1.502(5) Å, C-F = 1.397(4) Å, C-H = 1.097(2) Å. ∠CCF = 110.4(2)°, ∠CCH(av.) = 113.6(4)°. Evidence is presented to show that the electron diffraction data for C2H5F are not compatible with values for the bond angles deduced spectroscopically.  相似文献   

12.
Five new complex compounds of the formula Ln(phen)2(NO3)3 were prepared. The X‐ray structural analyses indicate that they crystallize isostructurally in the monoclinic space group C2/c (no. 15) with cell dimensions for example for Pr(phen)2(NO3)3: a = 11.194(1) Å, b = 18.095(2) Å, c = 13.101(2) Å, β = 100.52(1)°, V = 2609.1(6) Å3, Z = 4. The crystal structures consist of [Ln(phen)2(NO3)3] complex molecules. The rare earth atoms are coordinated by four N atoms of two phen ligands and six O atoms of three nitrato groups to complete a distorted bicapped dodecahedron. The [Ln(phen)2(NO3)3] complex molecules are assembled via π‐π stacking interactions between the neighboring phen ligands to form 1D columnar chains, which are then arranged in the crystal structures according to pseudo 1D close‐packed patterns.  相似文献   

13.
The reaction of (OC)4Re[μ-E-HC? C(CO2Me)CS2]Re(CO)4, 1 with EtNH2 yielded two new complexes: Re(CO)4[C(H)? C(CO2Me)C(NHEt)? S], 2 , (52%) and Re(CO)3(NH2Et)[C(H)? C(CO2Me)C(NHEt)=S], 3a (24%) by competitive attack of the EtNH2 at the dithiocarboxylate grouping and at the hydrogen substituted olefinic carbon atom in 1 . In both cases there is a loss of one of the rhenium groupings. The reaction of the sulfurized and oxygenated derivatives of 1, (OC)4Re[EC(H)C(CO2Me)CS2]Re(CO)4, 4a (E=S), 4b (E=O) with EtNH2 yielded Re(CO)4[C(H)=C(CO2Me)C(NHEt)=S], 5a , the parent carbonyl of 3a , by exclusive attack of the amine at the hydrogen substituted olefinic carbon atom. The reaction of (OC)4Re[μ-SC(S)C(CO2Me)C(H)S]Re(CO)4, 6a (an isomer of 4a ) with EtNH2 produced a similar result. The reaction of 4a with Et2NH yielded Re(CO)4[μ-S2C=C(CO2Me)C=NEt2], 5b an N-ethyl substituted derivative of 5a . These results indicate that the addition of certain heteroatoms can have a directing effect upon the reactivity of these compounds with amines. Compounds 2 and 5a were characterized by single crystal x-ray diffraction analyses. Crystal Data: For 2 : space group = P1, a = 10.782(1) Å, b = 14.721(2) Å, c = 9.940(2) Å, a = 91.57(1)°, β = 93.61(1)°, γ = 70.774(9)°, Z = 4, 4516 reflections, R = 0.047 and for 5a : space group = P21/n, a = 11.389(2) Å, b = 9.660(2) Å, c = 14.756(3) Å, β = 103.36(2)°, Z = 4, 1601 reflections, R = 0.022.  相似文献   

14.
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   

15.
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   

16.
Lanthanide triflates have been used to incorporate NdIII and SmIII ions into the 2.2.2‐cryptand ligand (crypt) to explore their reductive chemistry. The Ln(OTf)3 complexes (Ln=Nd, Sm; OTf=SO3CF3) react with crypt in THF to form the THF‐soluble complexes [LnIII(crypt)(OTf)2][OTf] with two triflates bound to the metal encapsulated in the crypt. Reduction of these LnIII‐in‐crypt complexes using KC8 in THF forms the neutral LnII‐in‐crypt triflate complexes [LnII(crypt)(OTf)2]. DFT calculations on [NdII(crypt)]2+], the first NdII cryptand complex, assign a 4f4 electron configuration to this ion.  相似文献   

17.
Lanthanide triflates have been used to incorporate NdIII and SmIII ions into the 2.2.2-cryptand ligand (crypt) to explore their reductive chemistry. The Ln(OTf)3 complexes (Ln=Nd, Sm; OTf=SO3CF3) react with crypt in THF to form the THF-soluble complexes [LnIII(crypt)(OTf)2][OTf] with two triflates bound to the metal encapsulated in the crypt. Reduction of these LnIII-in-crypt complexes using KC8 in THF forms the neutral LnII-in-crypt triflate complexes [LnII(crypt)(OTf)2]. DFT calculations on [NdII(crypt)]2+], the first NdII cryptand complex, assign a 4f4 electron configuration to this ion.  相似文献   

18.
The reaction of TbCl3 with K[2,4-(CH3)2 C5H5] at 0°C in THF followed by crystallization at ?90°C led to a pale yellow hexagonal prismatic crystalline product [2,4-[CH3)25-C5H5]3-Tb·1/ 2THF , which is highly sensitive to air and water and rapidly efflorescent at ambient temperature. The single crystal X-ray diffraction data of the compound have been collected at low temperature (-60°C) and the crystal structure has been solved by heavy atom method. It belongs to triclinic system, space group P1 with lattice parameters α=8.477 Å , b=12.583 Å , c=12.858 Å , α=118.08°, β=91.38°, γ=108.75°, V=1120.36 Å3 and Z=2. Least-squares refinement converged to a final value R=0.043. The compound possesses an idealized C3h symmetry with three 2,4dimethylpentadienyl ligands bound to the central terbium atom in a pentahapto mode (η5). Each unit cell contains two molecules of [2,4-(CH3)25-C5H5]3Tb and one molecule of solvent THF, of which the role in the lattice has been discussed in detail.  相似文献   

19.
The ligand 2,6-bis(1-methylbenzimidazol-2-yl)pyridine (mbzimpy, 1 ) reacts with EuIII to give [Eu(mbzimpy)(NO3)3(CH3OH)] [ 4 ] whose crystal structure (EuC22H21N8O10, a = 7.658(3) Å, b = 19.136(2) Å, c = 8.882 Å, β = 104.07(1)°, monoclinic, P21, Z = 2) shows a mononuclear structure where EuIII is ten-coordinate by a meridional tridentate mbzimpy ligand, three bidentate nitrates, and one CH3OH molecule, leading to a low-symmetry coordination sphere around the metalion. Essentially the same coordination is found in the crystal structure of [Eu(obzimpy)(NO3)3] ( 8 ) (EuC35H45N8O9, a = 9.095(2) Å, b = 16.624(2) Å, c = 26.198(6) Å, β = 95.85(1)°, monoclinic, P21/c, Z = 4) obtained by reaction of 2,6-bis(1-octylbenzimidazol-2-yl)pyridine (obzimpy, 2 ) with EuIII. Detailed photophysical studies of crystalline [Ln(mbzimpy)(NO3)3(CH3OH)] and [Ln(obzimpy)(NO3)3] complexes (Ln = Eu, Gd, Tb, Lu) show that 1 and 2 display 1ππ* and 3ππ* excited states very similar to those observed in 2,2′:6′,2″-terpyridine, leading to efficient ligand to LnIII intramolecular energy transfer. Spectroscopic results show that an extremely efficient mbzimpy-to-EuIII transfer occurs in [Ln(mbzimpy)(NO3)3(CH3OH)] and in the case of TbIII, a TbIII-to-mbzimpy back transfer is also implied in the deactivation process. The origin of these peculiar effects and the influence of ligand design by going from mbzimpy to obzimpy are discussed. 1H-NMR and luminescence data indicate that the structure found in the crystal is essentially maintained in solution.  相似文献   

20.
Synthesis and Molecular Structure of [Al(SiMe3)3(DBU)] (DBU = 1,8-Diazabicyclo[5.4.0]undec-7-ene) [Al(SiMe3)3(OEt2)] reacts with DBU (DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene) at 0 °C yielding [Al(SiMe3)3 · (DBU)] ( 1 ). 1 was characterised spectroscopically (1H, 13C, 29Si, 27Al NMR, IR, MS) and by X-ray structure determination [monoclinic, C2/c, a = 33.053(2), b = 9.307(1), c = 20.810(1) Å, β = 124.07(2)°, V = 5302.4(5) Å3, Z = 8, 218(2) K]. 1 does not react with [Cp2ZrCl2] even in boiling toluene.  相似文献   

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