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1.
The observed difference in transition strength for (SF6)2, (SiF4)2 and (SiH4)2 IR-predissociation spectra is explained by induction effects (μ012/R126) which have to be included in the interaction Hamiltonian in addition to the dominant dipole-dipole term (μ012/R123).  相似文献   

2.
The geometric structures and conformational properties of trifluoromethanesulfonic anhydride, (CF3SO2)2O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF3SO2)2CF2 have been studied by gas electron diffraction (GED) and ab initio calculations (HF/3–21G*). The calculations predict for both systems two stable conformers with C2 symmetry and one with C1 symmetry. In both compounds structures with C2 symmetry and dihedral angles SOSC ≈ 100° ((CF3SO2)2O) and SCSC≈ 150° ((CF3SO2)2CF2 are lowest in energy. According to the GED analyses the dominant conformer of (CF3SO2)2O2 possesses C2 symmetry with SOSC dihedral angles of 99.1(14)°. The presence of up to 30% of the two other conformers cannot be excluded; for (CF3SO2)2CF2 only one conformer with C2 symmetry and SCSC dihedral angles of 143(2)° is observed. A complete set of geometric parameters is given.  相似文献   

3.
The geometric structures and conformational properties of trifluoromethanesulfonic anhydride, (CF3SO2)2O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF3SO2)2CF2 have been studied by gas electron diffraction (GED) and ab initio calculations (HF/3–21G*). The calculations predict for both systems two stable conformers with C2 symmetry and one with C1 symmetry. In both compounds structures with C2 symmetry and dihedral angles SOSC ≈ 100° ((CF3SO2)2O) and SCSC ≈ 150° ((CF3SO2)2CF2) are lowest in energy. According to the GED analyses the dominant conformer of (CF3SO2)2O possesses C2 symmetry with SOSC dihedral angles of 99.1(14)°. The presence of up to 30% of the two other conformers cannot be excluded; for (CF3SO2)2CF2 only one conformer with C2 symmetry and SCSC dihedral angles of 143(2)° is observed. A complete set of geometric parameters is given.  相似文献   

4.
The reactions of (Me2AlH)3 with Me2AsNMe2, MeAs(NMe2)2, and As(NMe2)3 were investigated as a function of time at room temperature and over the temperature range −90 to 24°C by use of 1H and 13C NMR spectroscopy. (Me2AlH)3 was found to be very reactive toward the aminoarsines, even at −90°C, and no stable Me2AlH-aminoarsine adducts were observed. Instead, the initial stages of the reactions involved AS---N bond cleavage with the generation of highly reactive AlN- and AsH-bonded species. The subsequent course of each reaction and the final arsenic-containing product distribution depended upon the original AL:N stoichiometric ratio and the respective aminoarsine. When the Al:N ratio was 1:1, the reactions were straightforward for each aminoarsine. However, in every case, [Me2AlNMe2]2 was the final AlN-containing product. Independent reactions were carried out to verify many of the proposed decomposition pathways that lead to thermodynamically stable products. The results of this study are compared with those of the analogous, previously reported (Me3Al)2-aminoarsine systems. Additionally, a new synthetic route to [Me2AlAsMe2]3 has been established from the reaction of (Me2AlH)3 with Me2AsH.  相似文献   

5.
Estertn compounds, (MeO2CCH2CH2)2SnX2 [X2 = I2 (2); X2 = Br2 (9); X2 = Cl, Br (4)) or X2 = (NCS)2 (3)] have been obtained by halide exchange reactions of (MeO2CCH2CH2)2SnCl2. Crystal structure determinations of 2–4 revealed chelating MeO2CCH2CH2 units with distorted octahedral geometries at tin. The Sn---O bond lengths in the isothiocyanato complex, 3, are shorter [2.390(11) to 2.498(12), mean 2.439 Å], with the chelate bite angles, C---Sn---O, larger [74.3(7) to 78.2(6), mean 76.0°] than those in the halide analogues 2 and 4 [Sn---O = 2.519(2) to 2.541(8), mean 2.530 Å; C---Sn---O 72.8(3) to 73.9(4), mean 73.3°]. 1H, 13C and 119Sn NMR and IR spectra of 2–4 and 9 were determined in CDCl3 solution: the NMR spectra of (MeO2CCH2CH2)2SnX2 show the following trends: (i) both δ1H and δ13C, increase and (ii) both 2J (Sn---H) and 1J(Sn---C) decrease in the sequence X2 = (NCS)2, Cl2, ClBr, Br2 and I2. The MeO2CCH2CH2 and dmio groups (dmio = 1,3-dithiole-2-one-4,5-dithiolato) are all chelating groups in (MeO2CCH2CH2)2Sn(dmio) (5). As shown by X-ray crystallography, the tin atom in the anion of solid [Q][MeO2CCH2CH2Sn(dmio)2] 6 (Q = NEt4) forms 5 strong bonds [to C and the 4 thiolato S atoms, Sn---S 2.459(2) to 2.559(2) Å], arranged in a near trigonal bipyramidal array. There is an additional Intramolecular but weaker, interaction with the carbonyl oxygen atom [Sn---O = 3.111(5) Å]; v(C=O) = 1714 cm−1 in solid 6 (Q = NEt4). NMR spectra of 5 and 6 are also reported.  相似文献   

6.
The binuclear molybdenum(II) complexes [Mo2(O2CCF3)4(PR3)2] (R = Ph, Et) act as templates for the self-condensation of 2-aminobenzaldehyde to give a new class of complexes in which a hydride ion bridges two molybdenum(III) centres, each of which carries a tetradentate macrocyclic ligand (C). The new hydrido complexes [Mo2(C)2 (H)(O2CCF3)3(PPh3)2] (I), [Mo2(C)2(H)2(O2CCF3)2(PPh3)2] (II), and [Mo2(C)2 (H)2(O2CCF3)2(PEt3)2]2 (V) exist in two or more isomeric forms as shown by their IR, 1H, 31P and 19F NMR spectra. Substitution with thiocyanate, nitrate and tetraphenylborate anions gives the new products [Mo2(C)2(H)(CO)(NCS)3(PPh3)2] (III), [Mo2(C)2 (H)2(O2CCF3)(NO3)(PPh3)2] (IV), [Mo2(C)2(H)(O2CCF3)(PPh3)2](BPh4)2 (VI) and [Mo2(C)2(H)2(O2CCF3)(PEt3)2](BPh4) (VII), which also exist in isomeric forms.  相似文献   

7.
The coordinating properties of the trifluoromethyl elemental compounds Me2PP(CF3)2 and Me2AsP(CF3)2 have been studied by the synthesis and spectroscopic investigations (IR, NMR, MS) of their complexes cis-M(CO)4L2 (A), [(CO)4ML]2 (B) and [(CO)5M]2L (C) (M = Cr, Mo, W). Complexes of type A with L = Me2PP(CF3)2 are obtained in good yield by reaction with M(CO)4NBD (NBD = norbornadiene), whereas with L = Me2AsP(CF3)2 the homobinuclear compounds B are formed. The attempt to prepare the cis-M(CO)4[Me2AsP(CF3)2]2 complexes by treating M(CO)4(Me2AsH)2 with P2(CF3)4 is successful only for M = W. Binuclear compounds of type B or C, in general, can be prepared by stepwise reaction of the ligands with either M(CO)4NBD or M(CO)5THF.  相似文献   

8.
The P-functional organotin dichloride [Ph2P(CH2)3]2SnCl2 (3) is synthesized by reaction of Ph2P(CH2)3MgCl with SnCl4 independently of the molar ratio of the starting compounds. The corresponding organotin trichlorides Ph2P(CH2)nSnCl2R (4: n=2, R=Cl; 5: n=3, R=Cl; 6: n=3, R=Me) are formed in a cleavage reaction of Ph2P(CH2)nSnCy3 (n=2, 3) with SnCl4 or MeSnCl3, respectively. The main features of the crystal structures of 3–6 are both intra- and intermolecular PSn coordinations and the existence of intermolecular Sn---ClSn bridges. For further characterization of the title compounds, the adducts 4(Ph3PO)2 (7) and 5(Ph3PO) (8), as well as the P-oxides and P-sulfides of 3–6 (9–15), are synthesized. The results of crystal structure analyses of 7, 11, 12, and 14 are reported. The structures of 9–15 are characterized by intramolecular P=XSn interactions (X=O, S). A first insight into the structural behavior of the compounds 3–15 in solution is discussed on the basis of multinuclear NMR data.  相似文献   

9.
Infrared and Raman spectra on Na3H(SO4)2, K3 H(SO4)2 and (NH4)3 H(SO4)2 crystals have been investigated at 300 and 100 K in the 4000 to 30 cm−1 region. An assignment of bands in terms of OH group frequencies and more or less distorted tetrahedra of ammonium and sulphate ions is given. The crystallographic and spectroscopic symmetry and/or dissymetry of OHO hydrogen bonds linking sulphate ions into dimers is discussed using OH group frequencies and the splitting of the v1 (SO4) Raman bands as criteria. In the particular case of (NH4)3H(SO4)1 compound containing several solid phases it can be shown that the room temperature phase (II) is strongly disordered, principally because of an orientational disorder of ammonium ions, and that a progressive ordering takes place with temperature lowering.  相似文献   

10.
The compounds K4Ti(O2)4·2H2O, K3Ta(O2)2F4 and K2V2O3(O2)2F2 undergo photolysis in the solid state. The photolysis kinetics obey the parabolic rate equation p = kt1/2 and indicate a monoexcitation process for the photolysis. These features are similar to those reported previously for peroxo complexes. The mechanism of evolution of oxygen reported earlier appears to be the same in all these solids.  相似文献   

11.
An X-ray crystal structure determination for the bimetallic complex Mn2(CO)8-[P(NMe2)3]2 reveals that the P(NMe2)3 ligands are trans to the Mn---Mn bond and the Mn---Mn bond distance is relatively long, 2.946(1) Å.  相似文献   

12.
Treatment of 1,2-trans-C5H8(PCl2)2 with 1,2-C2H4(NHPr-i)2 gave the C2-symmetric perhydro-1,6,2,5-diazaphosphocine C5H8{P(Cl)N(Pr-i)CH2}2-cyclo, which produced dissymmetric C5H8(PPh2){P[N(Pr-i)CH2]2-cyclo} on further reaction with PhMgBr. Cleavage of the P---N bonds with gaseous HCl afforded C5H8(PPh2)(PCl2), which was converted to C5H8(PPh2){P(OPh)2}2 by reaction with phenol. All chiral P,P derivatives were obtained as racemates as well as resolved (1R,2R)- and (1S,2S)-enantiomers.  相似文献   

13.
The molecular structure of [Zr(NMe2)4]2 has been determined by an x-ray study and shown to involve a central Zr2N8 moiety involving the fusing of two trigonal bipyramidal units along a common axial-equatorial edge. The terminal Zr---NMe2 units have trigonal planar coordination about the nitrogen atoms: Zr---N = 2.050(5) and 2.104(5) Å, and Zr---N (bridge) = 2.224(3) and 2.453(4) Å for equatorial and axial bonds, respectively. The Zr---Zr distance is 3.704(1) Å as expected for a non-M---M bonding bridged compound. In tetrahydrofuran solution, Zr(NMe2)4 and LiNMe2 react irreversibly giving Zr(NMe2)6 Li2(THF)2 which has been isolated and characterized by an X-ray study. The central ZrN6 octahedral moiety is capped on two opposite faces by Li atoms which are also coordinated to an oxygen atom of a THF molecule. Pertinent distances are: Zr---N = 2.22(7) (av.), N---Li = 2.155(25) (av.) and Li---O = 1.915(10) Å.  相似文献   

14.
Toluene solutions of M2(NMe2)6 (M = Mo, W) react with mesitylene selenol (Ar′SeH) to give M2(SeAr′) 6 complexes. MO2(OR)6 (R = tBu, CH2tBu) react with excess> 6 fold) Ar′SeH to give Mo2 (SeAr′)6, whilst W2(OR)6(py)2 (R = iPr, CH2tBu) react with excess (> 6 fold) Ar′SeH to give W2(OR)2(SeAr′)4. Reaction of MO2(OPri)6 with Ar′SeH produces Mo2(OPri)2 (SeAr′)4 which crystallizes in two different space groups. These areneselenato complexes are air-stable and insoluble in common organic solvents. X-ray crystallographic studies revealed that the Mo2(SeAr′)6 and W2(SeAr′)6 compounds are isostructural in the solid state and adopt ethane-like staggered configurations with the following important structural parameters, M---M (W---W/Mo---Mo) 2.3000(11)/2.2175(13) Å, M---Se 2.430 (av.)/2.440 (av.) Å, M---M---SE 97.0° (av.)°. In the solid state W2(OiPr)2(SeAr′)4 adopts the anti-configuration with crystallographically imposed Ci symmetry and W---W 2.3077(7) Å, W---Se 2.435 (av.) Å, W---O 1.858(6) Å; W---W---SE 100.27(3)°, 93.8(3)° and W---W---O 108.41(17)°. Mo2(OPri)2(SeAr′) 4 crystallizes in both P and A2/a space groups in which the molecules are isostructural with each other and the tungsten analogue. Important bond lengths and angles are Mo---Mo 2.180(24) Å, Mo---Se 2.432(av.) Å, Mo---O 1.872(9) Å, Mo---Mo---Se 99.39(9)°, 94.71(8)°, Mo---Mo---O 107.55(28)°.  相似文献   

15.
The reaction between Ru2Cl(μ-O2CCH3)4 and molten p-tert-butylbenzamide led to the formation of Ru2Cl(μ-HNOCC6H4-p-CMe3)4. The polymeric structure of this insoluble compound was broken with AgBF4, in anhydrous thf, giving [Ru2(μ-HNOCC6 H4-p-CMe3)4(thf)2]BF4. The reaction of this cationic complex with OPPh3 gave [Ru2(μ-HNOCC6H4-p-CMe3)4(OPPh3)2]BF4. The compounds have been characterized by elemental analysis, spectroscopic data and magnetic measurements and the crystal structure of [Ru2(μ-HNOCC6H4-p-CMe3)4(OPPh3)2]BF4 was determined by X-ray crystallography. The asymmetric unit is composed of halves of two different crystallographically independent centrosymmetric cations. Each ruthenium(II,III) dimer is bonded to four bridging p-tert-butylbenzamidate ligands and to two axial triphenylphosphine oxide molecules. The Ru---Ru distances in the two dimeric cations of the unit cell are 2.281(2) and 2.280(2) Å. The compound has a non-polar 2 : 2 arrangement of the tert-butylbenzamidate ligands.  相似文献   

16.
Synthesis, structure, spectroscopy and thermal properties of complex [Co(NCS)2(hmt)2(H2O)2][Co(NCS)2(H2O)4] (H2O) (I), assembled by hexamethylenetetramine and octahedral Co(II) metal ions, are reported. Crystal data for I: Fw 387.34, a=9.020(8), b=12.887(9), c=7.95(1) Å, =96.73(4), β=115.36(5), γ=94.16(4)°, V=820(1) Å3, Z=2, space group=P−1, T=173 K, λ(Mo-K)=0.71070 Å, ρcalc=1.718567 g cm−3, μ=17.44 cm−1, R=0.088, Rw=0.148. An interesting two-dimensional network is assembled via hydrogen bonds through coordinated and free water molecules. The d–d transition energy levels of Co(II) ion are determined by UV–vis spectroscopy and calculated by ligand field theory. The calculated results agree well with experiment ones.  相似文献   

17.
Thermal displacement of coordinated nitriles RCN (R = CH3, C2H5 or n-C3H7) in [C5H5Fe(L2)(NCR)]X complexes (L2 = P(OCH3)3)2, (P(OC6H5)3)2 or (C6H5)2PC2H4P(C6H5)2 (DPPE)) by E(CH3)2 affords high yields of [C5H5Fe(L2)(E(CH3)2)]X compounds (E = S, Se and Te; X = BF4 or PF6). Spectroscopic data and ligand displacement reactions are presented and discussed together with related observations on [C5H5Fe(CO)2(E(CH3)2)]BF4 compounds. The molecular structure of [C5H5Fe(P(OCH3)3)2(S(CH3)2)]PF6 was determined by a single-crystal X-ray diffraction study: monoclinic, space group P21/n-C52h (No. 14) with a = 8.4064(12), b = 11.183(2), c = 50.726(8) Å, β = 90.672(13)° and Z = 8 molecules per unit cell. The coordination sphere of the iron atom is pseudo-tetrahedral with an Fe---S bond distance of 2.238 Å.  相似文献   

18.
A high yield synthesis of the carbonyl dithiocarbamato derivative Fe(CO)22-S2CNMe2)2 and Fe(η2-S2CNMe2)2 by photolysis with visible light of solutions containing Fe2(CO)9 or Fe3(CO)12 and [(η5-C5H5)(CO)3W(η1-SCSNMe2)] is reported.  相似文献   

19.
Polymerizations of ethylene have been carried out by using Cp2*Zr(NMe2)2 (Cp*=C5Me5) compound combined with common alkyl aluminums (AlR3) and methylaluminoxane (MAO) as cocatalysts. The AlMe3 cocatalyzed system showed no activity due to the formation of stable but inactive heterodinuclear [Cp2*2Zr(μ-Me)2AlMe2]+ cations; however, the bulkier AlR3 [AlEt3, Al(i-Bu)3 and Al(i-Bu)2H] cocatalyzed systems showed very high activities. Especially, Cp2*Zr(NMe2)2/Al(i-Bu)3 catalyst showed higher catalytic activity and produced higher molecular weight (MW) polymer than Cp2*Zr(NMe2)2/MAO catalyst, demonstrating both MAO and bulky AlR3 are effective cocatalysts for Cp2*Zr(NMe2)2 compound.  相似文献   

20.
(C6H5)3MX2 (M = As, Sb; X = OCOCF3 and M = Sb, Bi; X = SO3F, SO3CF3) compounds prepared by the interaction of triphenylmetal(V) substrates with (CF3CO)2O, (CF3SO2)2O and (FSO2)2O have been characterized by molecular weight determination, elemental and spectroscopic (IR, 1H and 19F NMR, mass) analyses.  相似文献   

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