首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 437 毫秒
1.
Oxidative Fluorination of (CF3)(R) (R = CF3, Cl) and the Crystal Structure of (CF3)(Cl) F+ AsF6? Oxidative fluorination of (CF3)(R) (R = CF3, Cl) with XeF+MF6? (M = As, Sb) in anhydrous HF results in formation of monofluorsulfonium hexafluorometalates. The salts are characterized by vibrational, NMR, and mass spectra. (CF3)(Cl)F+ AsF6? crystallizes in the monoclinic space group P21/c with a = 9.955(10) Å, b = 11.050(5) Å, c = 12.733(15) Å, β = 97.77(5)°, and Z = 4.  相似文献   

2.
Reaction of Cyclopentadienyl Substituted Molybdenum(V) Tetrachlorides with LiPH(2,4,6-Bu C6H2) and KPPh2(Dioxane)2. Crystal Structures of [Cp0Mo(μ? Cl)2]2 and [Cp Mo2(μ? Cl)3(μ? PPh2)] (Cp0 = C5Me4Et) The reaction of [Cp0Mo(CO)3]2 (Cp0 = C5Me4Et) and [Cp′Mo(CO)3]2 (Cp′ = C5H4Me) with PCl5 in CH3CN furnishes the Mo(V) complexes Cp0MoCl4(CH3CN) 1 and Cp′MoCl4(CH3CN) 2 in good yields. While 1 and 2 are reduced by LiPH(2,4,6-BuC6H2) to the Mo(III) complexes [Cp0Mo(μ? Cl)2]2 3 and [Cp′Mo(μ? Cl)2]2 4 , the reaction of 1 with KPPh2(dioxane)2 yields the reduction/substitution product [CpMo2(μ? Cl)3(μ? PPh)] 5 in low yield. 1 – 4 were characterized spectroscopically (i.r., mass, 3 and 4 also n.m.r.). An X-ray crystal structure determination was carried out on 3 and 5. 3 crystallizes in the triclinic space group P1 (No. 2) with a = 8.278(4), b = 12.508(7), c = 12.826(7) Å, α = 86.78(5), β = 81.55(2), γ = 75.65(4)°, V = 1 272.4 Å3 and two formula units in the unit cell (data collection at ? 67°C, 4 255 independent observed reflections, R = 2.9%); 5 crystallizes in the triclinic space group P1 (No. 2) with a = 11.536(8), b = 12.307(9), c = 13.157(9) Å, α = 91.41(6), β = 100.42(5), γ = 112.26(6)°, V = 1 688.7 Å3 and two formula units in the unit cell (data collection at ? 60°C, 6 147 independent observed reflections, R = 4.9%). The crystal structure of 3 shows the presence of centrosymmetric dimeric molecules with four bridging chloro ligands. In 5, two Mo atoms are bridged by three chloro ligands and one PPh2 ligand. The Mo? Mo bond length in 3 and 5 (2.600(2), 2.596(2) Å and 2.6388(8) Å) is in agreement with a Mo? Mo bond.  相似文献   

3.
The reactions of the bis(trimethylsilyl)acetylene permethylmetallocene complexes CpM(η2‐Me3SiC2SiMe3) (M = Ti ( 1 ), M = Zr ( 2 )) with H2O and CO2 were studied and compared to those of the corresponding metallocene complexes Cp2M(L)(η2‐Me3SiC2SiMe3) (M = Ti ( 3 ), L = – ; M = Zr, L = THF ( 4 )) to understand the influence of the ligands Cp(η5‐C5H5) and Cp*(η5‐C5Me5) as well as the metals titanium and zirconium on the reaction pathways and the obtained products. In the reaction of the permethyltitanocene complex 1 with water the dihydroxy complex CpTi(OH)2 ( 5 ) was formed. This product differs from the well‐known titanoxane Cp2TiOTiCp2 which was obtained by the reaction of the corresponding titanocene complex 3 with water. The reaction of the permethylzirconocene complex 2 with water gives the mononuclear alkenyl zirconocene hydroxide 6 . An analogous product was assumed as the first step in the reaction of the corresponding zirconocene complex 4 with water which ends up in a dinuclear zirconoxane. In the conversion of the permethylzirconocene complex 2 with carbon dioxide the mononuclear insertion product 7 was formed by coupling of carbon dioxide and the acetylene. In contrast, the corresponding zirconocene complex 4 affords, by an analogous reaction, a dinuclear complex. In additional experiments the known complex CpZr(η2‐PhC2SiMe3) ( 8 ) was prepared, starting from CpZrCl2 and Mg in the presence of PhC≡CSiMe3. This complex reacts with carbon dioxide resulting in a mixture of the regioisomeric zirconafuranones 9 a and 9 b . From these in the complex 9 a , having the SiMe3 group in β‐position to the metal, the Zr–C bond was quickly hydrolyzed by water to give the complex CpZr(OH)OC(=O)–C(SiMe3)=CHPh ( 10 a ) compared to complex ( 9 b ) which gives slowly the complex CpZr(OH)OC(=O)–CPh=CH(SiMe3) ( 10 b ).  相似文献   

4.
The reactions have been studied competitively over the range of 28–182°C by photolysis of mixtures of Cl2 + C2F5I+ CH4. We obtain where θ = 2.303RT J/mol. The use of published data on reaction (2) leads to log (k1cm3/mol sec) = (13.96 ± 0.2) ? (11,500 ± 2000)/θ.  相似文献   

5.
Two coordination polymers {[Cd(phen)](C6H8O4)3/3} ( 1 ) and {[Cd(phen)](C7H10O4)3/3} · 2H2O ( 2 ) were structurally characterized by single crystal X‐ray diffraction methods. In 1 (C2/c (no. 15), a = 16.169(2)Å, b = 15.485(2)Å, c = 14.044(2)Å, β = 112.701(8)°, U = 3243.9(7)Å3, Z = 8), the Cd atoms are coordinated by two N atoms of one phen ligand and five O atoms of three adipato ligands to form mono‐capped trigonal prisms with d(Cd‐O) = 2.271‐2.583Å and d(Cd‐N) = 2.309, 2.390Å. The [Cd(phen)] moieties are bridged by adipato ligands to generate {[Cd(phen)](C6H8O4)3/3} chains, which, via interchain π—π stacking interactions, are assembled into layers. Complex 2 (P1¯(no. 2), a = 9.986(1)Å, b = 10.230(3)Å, c = 11.243(1)Å, α = 66.06(1)°, β = 87.20(1)°, γ = 66.71(1)°, U = 955.7(2)Å3, Z = 2) consists of {[Cd(phen)](C7H10O4)3/3} chains and hydrogen bonded H2O molecules. The Cd atoms are pentagonal bipyramidally coordinated by two N atoms of one phen ligand and five O atoms of three pimelato ligands with d(Cd‐O) = 2.213—2.721Å and d(Cd‐N) = 2.329, 2.372Å. Through interchain π—π stacking interactions, the {[Cd(phen)](C7H10O4)3/3} chains resulting from [Cd(phen)] moieties bridged by pimelato ligands are assembled in to layers, between which the hydrogen bonded H2O molecules are sandwiched.  相似文献   

6.
1,4-Diaza-1,3-diene Compounds of Early Transition Metals. σ-Donor and π-Acceptor Complexes of Zirconium and Hafnium with perphenyl-substituted DAD Ligands – a Comparison of Structures Reaction of 1,4- D i a za-1,3- d ienes (DAD) with the Lewis-acid ZrCl4 affords σ-donor-complexes of composition ZrCl4 · DAD. The X-ray analysis of the ( 2c ) (space group P1 , triclinic; a = 11.339(2), b = 11.845(2), c = 12.415(3) Å, α = 107.94(2), β = 107.26(2), γ = 104.73(2)°, Z = 2, R1 = 0.0266) shows that both N-atoms of the s-cis-configurated DAD-ligand occupy two corners of a distorted octahedron. There is only slight difference between the C?N bond lengths of the coordinated and noncoordinated ligand. In the homoleptic DAD-complexes of the type M(DAD)3 [M = Zr ( 4b ), Hf ( 5b ), R = C6H4-4-Me] the DAD-ligands more act as π-acceptor ligands. X-ray analysis shows that the complexes [M = Zr ( 4b ), Hf ( 5b ), R = C6H4-4-Me] have the identical structure motive and crystallize in the triclinic space group P1 ( 4b : a = 14.904(1), b = 15.451(2), c = 19.584(4) Å, α = 112.08(1), β = 94.36(1), γ = 97.60(1)°, Z = 2, R1 = 0.0911; 5b a = 14.798(2), b = 18.226(2), c = 22.902(2) Å, α = 71.62(1), β = 72.38(1), γ = 87.27(1)°, Z = 2, R1 = 0.0644). The six N-atoms form a distorted octahedron in both complexes. The planarity of the five-membered rings and the almost similar C?N and C? C bond lengths are typical of the π-acceptor function of the diazadienes in 4b and 5b . The steric hindrance in 4b und 5b results in a dynamical behavior and a asymmetrical distortion at low temperatures as was observed by n.m.r.  相似文献   

7.
The title compound, Cp2TiR (Cp=C5H5; R=2,6-(4-MeC6H4)2C6H3), 1, was prepared by reaction of RLi with [Cp2TiCl]2. Compound 1 was characterized by elemental analysis, EPR, and single crystal X-ray crystallography. The title compound crystallizes in the monoclinic space group C2/c with the following unit cell dimensions: a=11.1466(7) Å, b=16.4429(11) Å, c=13.0786(8) Å; b=106.2040(10)°;V=2301.9(3) Å3. The EPR spectrum of 1 displays two signals, a high field signal at g=1.979 and a lower field signal at g=1.959. Significantly, 1 is a sterically encumbered m-terphenyl-stabilized trivalent titanocene paramagnetic complex and may be a practical one-electron reducing reagent.  相似文献   

8.
Azodicarboxylates and Diazoacetates as Reactants of the Ferriophosphaalkene [Cp*(CO)2FeP=C(Ph)NMe2] Reaction of equimolar amounts of the ferriophosphaalkene [Cp*(CO)2FeP=C(Ph)NMe2] ( 1 ) and diethyl azodicarboxylate afforded the complex (C5Me4CH2)(CO)2Fe ( 3 ) as the result of a cheletropic [1+4] cycloaddition with subsequent transprotonation. The diazoacetates N2=CHCO2R ( 8a :=tBu; 8b :Et) and 1 gave rise to the formation of the N‐metallated 1, 2, 3‐diazaphospholes [Cp*(CO)2Fe‐ ] ( 11a, b ). Compounds 3, 11a and 11b were characterized by means of elemental analyses and spectroscopy (IR, 1H, 13C{1H}, 31P{1H}‐NMR). The molecular structure of 11a was determined by X‐ray diffraction analysis.  相似文献   

9.
The 2′-cyclopalladated imine complex , reacts with CO in MeOH to afford the 2′-substituted aryl imine 2′-CO2CH3-5′-OCH3? C6H3CH?NTol (Tol = C6H4-4-CH3). The product of this reaction can be altered by changing the bridging ligand from AcO to Cl, in which case only the 5-membered ring heterocyclic compound is obtained. [Pd(μ-OAc)( 1a )]2 with 2 equiv. of Ph3P and CO (1 atm) gives the heterocyclic which arises from two CO insertion reactions, whereas [PdX( 1a )]2 (X = AcO, Cl) with 4 equiv. of C?NBut and 4 equiv. of Ph2PCH2CH2PPh2 affords the heterocyclic ketenimine [PdCl( 1a )]2 reacts with CH2?CHCO2CH2CH3 to afford 2′(? CH?CHCO2CH2CH3)-5′-OCH3C6H3CHO, and [Pd(μ-OAc)( 1a )]2 with I2 to give 2′-I-5′-OCH3C6H3CHO. Excess CH3O2CC?CCO2CH3 reacts with various substituted cyclopalladated Schiff's bases in MeOH to afford which we formulate as possessing two Pd? C bonds, and one coordinated ester O atom. The X-ray crystal structure of [Pd(μ-OAc)( 1a )]2 has been determined; relevant bond lengths [Å] and bond angles [°] are: Pd? O(1), 2.139(6), Pd? O(2), 2.026(6), Pd? N, 2.039(6), Pd? C(2′), 1.951(8), Pd? Pd, 3.113(1), N? Pd? C(2′), 80.9(3), N? Pd? O(1), 97.5(2), C(2′)? Pd? O(2), 91.7(3), O(1)? Pd? O(2), 89.2(2).  相似文献   

10.
On the Insertion into the Lanthanide–Carbon Bond. Synthesis and Structure of [Cp Sm(C6H5CH2NNO)]2 and [K(18-crown-6)Cp Yb(NCS)2] The compound [CpSm(CH2C6H5)(thf)] was investigated, regarding its reactions with small molecules. The main subject was to detect an insertion into the Ln–C bond. With N2O an insertion reaction is observed, yielding the dimer [CpSm(C6H5CH2NNO)]2 ( 1 ). The structural data of 1 was collected by a single crystal X-Ray diffraction analysis. (Space group P 1, Z = 1, a = 982.8(2) pm, b = 1052.2(2) pm, c = 1383.8(3) pm, α = 89.29(3)°, β = 73.64(3)°, γ = 66.41(3)°). In the dimer, the two Samarium ions are linked via an (η1 : η2) bridge by two benzyl diazotato ligands. A nearly planar six-membered central Sm2N2O2-ring is formend. Two pentamethylcyclopentadienyl ligands complete the coordination sphere of each Samarium ion, which are thus surrounded by four ligands each and have a distorted tetrahedral coordination geometry. An insertion of a SCN fragment in the Ln–C bond could not be observed. The substitution of the benzyl ligand leads to a polymeric chain structure. The new compound [K(18-crown-6)CpYb(NCS)2] 2 contains a tetrahedrally coordinated Yb(III)-ion. (Space group P21/n}, Z = 4, a = 1640.6(3) pm, b = 1482.2(3) pm, c = 1674.5(3) pm, β = 102.82(1)°).  相似文献   

11.
Transition Metal‐substituted Phosphaalkenes. 42 Reactivity of the Ferriophosphaalkenes [(η5‐C5Me5)(CO)2FeP=C(NR )R2] (NR = NMe2, NC5H10, R2 = Ph, t Bu) towards Protic Acids, Alkylation Reagents, and [{( Z )‐Cyclooctene}Cr(CO)5] The reaction of equimolar amounts of [(η5‐C5Me5)(CO)2FeP=C(NR )R2] ( 2 a : NR = NMe2, R2 = Ph; 2 b : NMe2. tBu; 2 c : NC5H10, Ph) and etherial HBF4 gave rise to the formation of [(η5‐C5Me5)(CO)2FeP(H)C(NR )R2] (BF4) ( 3 a – c ) which were isolated as light red powders. Compounds 2 a – c were converted into [(η5‐C5Me5)(CO)2FeP(Me)C(NR )R2] (SO3CF3) ( 4 a – c ) by treatment with methyl trifluoromethane sulfonate. In addition 2 a and Me3SiCH2OSO2CF3 afforded light red [(η5‐C5Me5)(CO)2FeP(CH2SiMe3)C(NMe2)Ph](SO3CF3) ( 5 ). The black complex [(η5‐C5Me5)(CO)2FeP{Cr(CO)5}C(NMe2)Ph] ( 6 ) resulted from the combination of 2 a with [{(Z)‐cyclooctene}Cr(CO)5]. The novel products were characterized by elemental analyses and spectra (IR, 1H‐, 13C‐ und 31P‐NMR).  相似文献   

12.
The title compounds 3‐5 are accessible by treatment of P(C6H4CH2NMe2)3( 1 ) with CuX ( 2a : X = Cl, 2b : X = Br, 2c : X = I) in the ratio of 1:1 or 1:2 in very good yields. Reaction of 1 with equimolar amounts of 2a affords the copper(I) chloride [P(C6H4CH2NMe2)3]CuCl ( 3 ). With a further equivalent of 2a homobimetallic [P(C6H4CH2NMe2)3]Cu2Cl2 ( 4 ) is formed, which also can be synthesized by the reaction of 1 with two equivalents of 2a. Complex 3 reacts with CuX (X = Br, I)to afford [P(C6H4CH2NMe2)3]Cu2ClX ( 5a : X = Br; 5b : X = I) in which mixed halides are present. The newly synthesized complexes 3‐5 were characterized by elemental analyses, by their IR‐, 1H‐, 13C{1H}‐ and 31P{1H}‐NMR spectra as well as by mass spectrometrical studies. The solid‐state structures of complexes 3 and 4 are reported. Mononuclear 3 crystallizes in the monoclinic space group P21/c with the cell parameters a = 14.285(2), b = 10.853(2), c = 17.425(2) Å , β = 103.310(10)?, V = 2628.9(7) Å 3 and Z = 4 with 4053 observed unique reflections; R1 = 0.0314. The crystal structure of 3 consists of monomeric molecules with planar coordinated copper(I) centres (CuClNP). Homobimetallic 4 crystallizes in the monoclinic space group P21/n with a = 23.905(4), b = 10.874(3), c = 25.314(5), β = 99.130(10)?, V = 6497(2) /Aring; 3 and Z = 4 with 9021 observed unique reflections; R1 = 0.0480. In 4 one of two copper(I) centres possesses a distorted trigonal‐pyramidal environment, while the other one is almost square‐pyramidal coordinated. The Cu2Cl2 segment resembles to a building block which is set up by a contact ion pair consisting of Cu+ and [CuCl2] , respectively.  相似文献   

13.
Crystal Structures of the Fluorochloroplatinates(IV) cis-[(C5H5N)2CH2][PtF4Cl2], trans-[(C5H5N)2CH2][PtF4Cl2] · H2O, and [(C5H5N)2CH2][PtF5Cl] The complex ions cis-[PtF4Cl2]2?, trans-[PtF4Cl2]2? and [PtF5Cl]2? have been synthesized by stereoselective ligand exchange reactions utilizing the trans effect and are separated by ion exchange chromatography on diethylaminoethyl cellulose. These anions form stable AB-type salts with the doubly charged cation dipyridiniomethane, [(C5H5N)2CH2]2+. X-ray structure determinations on single crystals of cis-[(C5H5N)2CH2][PtF4Cl2] ( 1 ) (monoclinic, space group P21/n with a = 10.379(10), b = 9.635(2), c = 13.738(2) Å, β = 99.142(10)°, Z = 4), trans-[(C5H5N)2CH2][PtF4Cl2] · H2O ( 2 ) (triclinic, space group P1 with a = 7.757(4), b = 10.059(7), c = 10.408(6) Å, α = 82.49(5), β = 68.92(4), γ = 75.46(4)°, Z = 2) and [(C5H5N)2CH2][PtF5Cl] ( 3 ) (orthorhombic, space group Pnma with a = 10.394(3), b = 13.320(2), c = 9.2694(10) Å, Z = 4), reveal the perfect ordering of the anion sublattice. The stronger trans influence of Cl compared with F is observed in asymmetric axes $ {\rm F}^ \bullet $? Pt? Cl′. The bond lengths Pt? $ {\rm F}^ \bullet $ are 0.026 Å (1.4%) longer and the Pt? Cl′ distances are 0.078 Å (3,3%) shorter in comparison with those of symmetrically coordinated axes. The weakening of the Pt? $ {\rm F}^ \bullet $ bond and the strengthening of the Pt? Cl′ bond is better recognizable from shifts of the stretching vibrations by 8% to lower and by 13% to higher frequencies, respectively. Correspondingly, the valence force constants are found to be 15% lower and 22% higher. The trans influence is observed most distinctly in the 19F-nmr spectra exhibiting the coupling constant 1J($ {\rm F}^ \bullet $Pt) to be 29% smaller than 1J(FPt).  相似文献   

14.
Using published data on the kinetics of pyrolysis of C2Cl6 and estimated rate parameters for all the involved radical reactions, a mechanism is proposed which accounts quantitatively for all the observations: The steady-state rate law valid for after about 0.1% reaction is and the reaction is verified to proceed through the two parallel stages suggested earlier whose net reaction is A reported induction period obtained from pressure measurements used to follow the rate is shown to be compatible with the endothermicity of reaction A, giving rise to a self-cooling of the gaseous mixture and thus an overall pressure decrease. From the analysis, the bond dissociation energy DH0(C2Cl5? Cl) is found to be 70.3 ± 1 kcal/mol and ΔHf3000(·C2Cl5) = 7.7 ± 1 kcal/mol. The resulting π? bond energy in C2Cl4 is 52.5 ± 1 kcal/mol.  相似文献   

15.
Phosphanediyl Transfer from Inversely Polarized Phosphaalkenes R1P=C(NMe2)2 (R1 = tBu, Cy, Ph, H) onto Phosphenium Complexes [(η5‐C5H5)(CO)2M=P(R2)R3] (R2 = R3 = Ph; R2 = tBu, R3 = H; R2 = Ph, R3 = N(SiMe3)2) Reaction of the freshly prepared phosphenium tungsten complex [(η5‐C5H5)(CO)2W=PPh2] ( 3 ) with the inversely polarized phosphaalkenes RP=C(NMe2)2 ( 1 ) ( a : R = tBu; b : Cy; c : Ph) led to the η2‐diphosphanyl complexes ( 9a‐c ) which were isolated by column chromatography as yellow crystals in 24‐30 % yield. Similarly, phosphenium complexes [(η5‐C5H5)(CO)2M=P(H)tBu] (M = W ( 6 ); Mo ( 8 )) were converted into (M = W ( 11 ); Mo ( 12 )) by the formal abstraction of the phosphanediyl [PtBu] from 1a . Treatment of [(η5‐C5H5)(CO)2W=P(Ph)N(SiMe3)2] ( 4 ) with HP=C(NMe2)2 ( 1d ) gave rise to the formation of yellow crystalline ( 10 ). The products were characterized by elemental analyses and spectra (IR, 1H, 13C‐, 31P‐NMR, MS). The molecular structure of compound 10 was elucidated by an X‐ray diffraction analysis.  相似文献   

16.
Selective Preparation of Twofold Diorganophosphido-bridged Metallatetrahedranes [Re2(MPR3)2(μ-PR2)2(CO)6] with Re2M2 Metal Core (M = Au, Ag) The reaction of the in situ prepared salt Li[Re2(AuPR)(μ-PR2)(CO)7Cl] (R = R′ = Cy ( 1 a ), R = Cy, R′ = Ph ( 1 b ), R = Ph, R′ = Cy ( 1 c ), R = Ph, R′ = Et ( 1 d ), R = Ph, R′ = Ph ( 1 e )) with one equivalent HPR in methanolic solution at room temperature yields the neutral cluster complexes [Re2(AuPR)(μ-PR2)(CO)7(ax-HPR) (R = R′ = R″ = Cy ( 2 a ), Ph ( 2 b ), R = R′ = Cy, R″ = Et ( 2 c ), R = Cy, R′ = R″ = Ph ( 2 d ), R = Cy, R′ = Ph, R″ = Et ( 2 e ), R = R″ = Ph, R′ = Et ( 2 f ), R = Ph, R′ = Cy, R″ = Et (2 g)). Photochemically induced these complexes react in the presence of the organic base DBU in THF solution to give the doubly phosphido bridged anions Li[Re2(AuPR)(μ-PR2)(μ-PR)(CO)6], which were characterized as salts PPh4[Re2(AuPR)(μ-PR2)(μ-PR)(CO)6] (R = R′ = R″ = Ph ( 3 a ), R = R′ = Ph, R″ = Cy ( 3 b ), R = Ph, R′ = Cy, R″ = Et ( 3 c ), R = R″ = Ph, R′ = Et ( 3 d )). These precursor complexes 3 then react with one equivalent of ClMPR (M = Au, Ag) to doubly phosphido bridged metallatetrahedranes [Re2(MPR3)2(μ-PR2)(μ-PR)(CO)6] (M = Au, R = R′ = R″ = Ph ( 4 a ), M = Au, R′ = Et, R = R″ = Ph ( 4 b ), M = Au, R = R′ = Ph, R″ = Cy ( 4 c ), M = Au, R = Cy, R′ = Ph, R″ = Et ( 4 d ), M = Ag, R = R′ = R″ = Ph ( 4 e )). All isolated cluster complexes were characterized and identified by the following analytical methods: NMR- (1H, 31P) and ν(CO) IR-spectroscopy and, additionally, complexes 2 b , 4 a and 4 e by X-ray structure analysis.  相似文献   

17.
The reaction of atomic hydrogen with isocyanic acid (HNCO) to produce the amidogen radical (NH2) and carbon monoxide, has been studied in shock-heated mixtures of HNCO dilute in argon. Time-histories of the ground-state NH2 radical were measured behind reflected shock waves using cw, narrowlinewidth laser absorption at 597 nm, and HNCO time-histories were measured using infrared emission from the fundamental v2-band of HNCO near 5 μm. The second-order rate coefficient of reaction (2(a)) was determined to be: cm3 mol?1 s?1, where f and F define the lower and upper uncertainty limits, respectively. An upper limit on the rate coefficient of was determined to be:   相似文献   

18.
The adduct 1,6‐di­amino­hexane–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2) is a salt {hexane‐1,6‐diyldiammonium–4‐[1,1‐bis(4‐hydroxyphenyl)ethyl]phenolate (1/2)}, C6H18N22+·2C20H17O3?, in which the cation lies across a centre of inversion in space group P. The anions are linked by two short O—H?O hydrogen bonds [H?O 1.74 and 1.76 Å, O?O 2.5702 (12) and 2.5855 (12) Å, and O—H?O 168 and 169°] into a chain containing two types of R(24) ring. Each cation is linked to four different anion chains by three N—H?O hydrogen bonds [H?O 1.76–2.06 Å, N?O 2.6749 (14)–2.9159 (14) Å and N—H?O 156–172°]. In the adduct 2,2′‐bipyridyl–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2), C10H8N2·2C20H18O3, the neutral di­amine lies across a centre of inversion in space group P21/n. The tris­(phenol) mol­ecules are linked by two O—H?O hydrogen bonds [H?O both 1.90 Å, O?O 2.7303 (14) and 2.7415 (15) Å, and O—H?O 173 and 176°] into sheets built from R(38) rings. Pairs of tris­(phenol) sheets are linked via the di­amine by means of a single O—H?N hydrogen bond [H?N 1.97 Å, O?N 2.7833 (16) Å and O—H?N 163°].  相似文献   

19.
Synthesis and Spectroscopic Characterization of some Pentacarbonyltungsten(0) Complexes with Various 1H-Phosphirene Ligands: Crystal Structures of , and The tungsten(0) complex 1 reacts upon heating with acetylene derivatives 2a–f in toluene to form benzonitrile and the complexes 4a–f ( 4a : R1 ? Ph, R2 ? H; 4b : R1 ? Ph, R2 ? CH3; 4c : R1 ? OEt, R2 ? H; 4d : R1 ? Ph, R2 ? CO2Et; 4e : R1, R2 ? CO2Me; 4f : R1, R2 ? SiMe3), which have been isolated by chromatography. Spectroscopic and mass spectrometric data are discussed. The crystal structures of the compounds 4a, b and d were determined by X-ray single crystal structure analysis ( 4a : space group P21/n, Z = 4, a = 937,5(2) pm, b = 2202,4(6) pm, c = 1266,3(4) pm, β = 108,94(4)°; 4b : space group P21/c, Z = 4, a = 1293,9(2) pm, b = 923,5(1) pm, c = 2223,4(3) pm, β = 92,385(6)°; 4d : space group P21/c, Z = 4, a = 955,2(2) pm, b = 3190,9(4) pm, c = 930,7(2) pm, β = 99,64(1)°).  相似文献   

20.
An Unusual System of Hydrogen Bonds in Rubidium Hydroxide Dihydrate, RbOH · 2 H2O RbOH · 2H2O was obtained by the reaction of Rb with H2O and dehydration of the resulting solution by concentrated sulfuric acid. The compound melts at 310 K. The structure was determined by X-ray single crystal methods: The H positions of H2O were found. The structure consists of a threedimensional H-bonded network of H2O molecules and OH?ions. Hydroxide ions are acceptors for four protons of four adjacent water molecules with d(O? O) = 2×2.59 Å and 2×2.82 Å. Oxygen of OH-ions is disordered over a distance of 1.27 Å. Rb has 8 H2O molecules as nearest neighbours, d(Rb? O) = 3.03 Å to 3.07 Å, OH?ions are further removed with d(Rb? O) ≥ 3.45 Å.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号