共查询到20条相似文献,搜索用时 15 毫秒
1.
High resolution vibration-rotation spectra of 13C 2H 2 were recorded in a number of regions from 2000 to 5200 cm −1 at Doppler or pressure limited resolution. In these spectral ranges cold and hot bands involving the bending-stretching combination levels have been analyzed up to high J values. Anharmonic quartic resonances for the combination levels ν 1 + mν 4 + nν 5, ν 2 + mν 4 + ( n + 2) ν 5 and ν 3 + ( m − 1) ν 4 + ( n + 1) ν 5 have been studied, and the l-type resonances within each polyad have been explicitly taken into account in the analysis of the data. The least-squares refinement provides deperturbed values for band origins and rotational constants, obtained by fitting rotation lines only up to J ≈ 20 with root mean square errors of ≈ 0.0003 cm −1. The band origins allowed us to determine a number of the anharmonicity constants xij0. 相似文献
2.
We have recorded and analyzed the molecular beam spectra of allene in the regions of the ν 1 + ν 5 and 2 ν 8 bands around 5947.5 and 6135.5 cm −1, respectively. The ν 1 + ν 5 band only shows minor perturbations and we suspect the presence of a doorway state that causes parallel Coriolis coupling to the bath states. Perpendicular Coriolis interactions do not seem to play an important role since the size of the matrix elements does not increase systematically with J′. The spectrum in the region of the 2 ν 8 band is more complicated; a total of six sub-bands has been identified with K = 0–2. Based on the lack of any systematic dependence on J′ and an inverse dependence of the coupling on K, we expect that neither parallel nor perpendicular Coriolis coupling is present in this band. The effective lifetime for both bands is calculated to be about 200 ps, which is very similar to the lifetimes of an acetylenic C---H stretch overtone. 相似文献
3.
The vibrational spectra of σ-(C 3H 5)Mn(CO) 5 are reported. Assignment of bands is made and carbonyl force constants are calculated. The results indicate that the Mn(CO) 5 moiety has C4ν symmetry. The calculated angle between the axial and equatorial carbonyl groups is approximately 95°. The bonding in this compound is very similar to that in (CH 3)Mn(CO) 5. In the far-infrared region, seven bands are expected in C4ν symmetry (3A1 + 4E), and all are observed. 相似文献
4.
The infrared absorption of mixtures of dimethyl ether and hydrogen halide (HX) in nitrogen at 13 K display relatively narrow bands in the range 650–800 cm −1 with an isotopic ratio ν H/ν D larger than 1.4 and weakly halogen dependent; these features are assigned to the antisymmetric O…H…O stretching within the [(CH 3) 2 O…H…O(CH 3) 2] +X − ion pair. With HI—ether mixtures, the intensity of the 660 cm −1 band decreases under infrared irradiation of the matrix, which might be due to the transfer of the proton back to the I − anion. 相似文献
5.
The crystal structure of the title compound has been determined. Crystals of [HgC1 2{μ-S(CH 2) 3NH(CH 3) 2}] are monoclinic, space group P2 1/ n, with a = 10.136(2), b = 6.519(1), c = 15.940(6) Å and β = 97.20(3)°. The structure consists of (---Hg---S---) n helicoidal chains linked by hydrogen bonding, which give rise to chemically unconnected layers along the (
02) planes. Each mercury is tetrahedrally coordinated to two terminal chlorine atoms and two bridging sulphur atoms. Assignments of ν as(SHgS) and ν s(SHgS) for this complex and its isostructural bromine analogue, and of ν s(C1HgC1) and ν s(BrHgBr) from IR and Raman spectroscopy are reported. Comparison of Hg---S frequencies with those reported for closely related compounds as well as correlation with Hg---S bond distances are made. 相似文献
6.
139La-NMR chemical shifts were measured for several anionic complexes of formulae Li(C 4H 8O 2) 3/2 [La(ν 3-C 3H 5) 4], [Li(C 4H 8O 2) 2][Cp′ nLa(ν 3-C 3]H 5) 4−n] (Cp′ = Cp(ν 5-C 5H 5); n = 1, 2 and Cp′ = Cp * (ν 5-C 5Me5); N = 1) and Li[R nLa(ν 3-C 3H 4) 4− n] (R = N(SiMe 3) 2; n = 1, 2 and R = CCsIMe 3; n = 4), as well as for neutral compounds for formulae La(ν 3-C 3H 5) 3L n (L = (C 4H 8O 2) 1.5, (HMPT) 2, TMED), Cp′ nLa(ν 3-C 3H 5) 3−n (Cp′= Cp(ν 5-Cp 5H 5), Cp *(ν 5-C 5Me 5); n = 1, 2) and La(ν 3-C 3H 2) 2X(THF) 2 X = Cl, Br, I). Typical ranges of the 139La-NMR chemical shifts were found for the different types of complex independent of number and kind of organyl groups directly bonded to lanthanum. Zusammenfassung139La-NMR-Spektroskopie wurde an einer Reihe anionischer Allyllanthanat(III)-Komplexe der Zusammensetzung
]- [La)ν3-C3H5)4, [Li(C4H8)2][Cp′nLa(ν3-C3H5)4−n(Cp′ = Cp(ν5-C5H5); n = 1, 2 und Cp′ = Cp * (ν5-C5Me5); N = 1) und Li[RnLa(ν3-C3H5)4−n (R = B(SiMe3)2; n = 1, 2 und R = CCSiMe3; n = 4 sowie neutraler Allyllanthan(III)-Komplexe der Zusammensetzung La(ν3-C3H5)3Ln (Ln = (C4H8O2)1.5, (HMPT)2, TMED), Cp′n, La(ν3-C3H5)3−n (Cp′ = Cp(ν5-C5H5), Cp * (ν5- Cp5Me5); n = 1, 2) und La(ν3-Cp3H5)2X(THF)2 (X = Cl, Br, I) durchgefürt. In Abhängikeit von der Anzahl und der Art der am Lanthan gebundenen Gruppen wurden für die verschieden Komplextypen charakteristische Resonanzbereiche ermittelt. 相似文献
7.
The SCF-RPA scheme is applied to the n → π* absorption band of cyclopentanone in its ( C2) ground-state nuclear configuration. Using the Cederbaum—Domcke algorithm, the effects of the (ν 3) C=O stretching, (ν 18) ring puckering and (ν 25) C=O out- of-plane vibrations are investigated. The calculated spectrum shows both allowed and vibronic components, in agreement with the experimental observations of Howard-Lock and King. 相似文献
8.
The vibrational characteristics of deuterated acetonitrile dissolved in isopropanol, dimethyl formamide (DMF), and dimethyl sulfoxide (DMSO) have been studied. Observed vibrational bands show substantial frequency shifts, the amounts of which vary almost linearly with concentration. The absorption feature in the region of 2220–2280 cm −1 was deconvoluted to the consisting absorption bands. The band at 2258 cm −1 of pure CD 3CN, which is on the low frequency side of the monomer CN stretch ( ν2), is attributed to the CN stretch of the dimer (ν′ 2). The shoulder found on the further low frequency side of the ν2 band, particularly in dilute solution, is believed to be due to ν5, and its frequency and intensity vary largely as a function of concentration along with those of other vibrational bands involved with the CD 3 group. The ν5 band of pure CD 3CN is believed to be active and located at about 2251 cm −1. Ab initio calculations have also been performed for the solute–solvent complexes, CD 3CN–DMF and CD 3CN–DMSO, at the MP2/6-31+G(2d,p) level assuming anti-parallel configurations. The calculated results show a good agreement with the observed results. 相似文献
9.
A series of novel heterobimetallic crown ether-like polyoxadiphosphaplatinaferrocenophanes cis-[1,1′-Fc(CH 2O(CH 2CH 2O) nCH 2CH 2PPh 2) 2]PtCl 2 ( n=1–3) (4a–c) was synthesized in good yield by cyclization of the bis(phosphine) ligands 1,1′-Fc(CH 2O(CH 2CH 2O) nCH 2CH 2PPh 2) 2 ( n=1–3) (3a–c) and (PhCN) 2PtCl 2 under high dilution conditions in CH 2Cl 2. The bisphosphines 3a–c are obtained by reaction of the corresponding diols 1,1′-Fc(CH 2O(CH 2CH 2O) nCH 2CH 2OH) 2 ( n=1–3) (1a–c) with: (i) CH 3SO 2Cl in CH 2Cl 2 and (ii) LiPPh 2 in THF. Although the X-ray crystal structure of 4a shows that the cavity is large enough for the encapsulation of small metal cations, inclusion experiments of 4a–c with Group 1 cations, and Mg 2+, or NH 4+ in solution applying NMR titration and cyclovoltammetric methods reveal no evidence for the formation of host–guest complexes for 4a,b. In the case of 4c only the addition of Na + or K + leads to an insignificant effect. 相似文献
10.
Three families of heterobimetallic compounds were obtained by reaction of [Mo(CO) 3(CH 3CN) 2(Cl)(SnRCl 2)] (R = Ph, Me) with P(4-XC 6H 4) 3 (X = Cl, F, H, Me, MeO). The type of compound obtained dependent on the solvent and concentration of the starting compound. So, [Mo(CO) 2(CH 3COCH 3) 2(PPh 3)(Cl)(SnRCl 2)]· nCH 3COCH 3 (R = Ph, n = 0.5; R = Me, n = 1) (type I) and [Mo(CO) 3{P(4-XC 6H 4) 3}(μ-Cl)(SnRCl 2)] 2 (R = Ph, X = Cl, F, H, Me, MeO; R = Me, X = Cl, F) (type II) were isolated from acetone solution in ca 0.05 M and 0.1 M concentrations, respectively. However, [Mo(CO) 3(CH 3CN) {P(4-XC 6H 4) 3}(Cl)(SnRCl 2)] (R = Ph, X = H; R = Me, X = Cl, F, H) (type III) were obtained from dichloromethane solution independently of the concentration used. All new complexes showed a seven-coordinate environment at molybdenum, containing Mo---Cl and Mo---Sn bonds. Mössbauer spectra indicated a four-coordination at tin for type III complexes. 相似文献
11.
The high-resolution infrared absorption spectrum of an equilibrium mixture of HCN and HCl in a static gas long-path absorption cell is recorded in the 2500–2900 cm −1 spectral region at 205 K. The spectrum shows rovibrational structure which has the typical appearance of a parallel band of a linear molecule and is assigned to the intramolecular H–Cl stretching vibration band ν 2 of the linear HCN–H 35Cl heterodimer. The rovibrational analysis of the band yield a band origin ν 0 of 2779.0968(12) cm −1 together with a value for the upper-state rotational constant B′ of 0.067722(2) cm −1. The observed red shift of 107 cm −1 for the ν 2 band of HCN–H 35Cl relative to the H–Cl stretching vibration band of monomer H 35Cl is in excellent agreement with results from the MP2/6−311++G** level of theory. The value of the upper-state rotational constant shows that the intermolecular hydrogen bond shortens by 0.022 Å upon intramolecular vibrational excitation of the ν 2 mode. 相似文献
12.
Six new cluster derivatives [Rh 2Co 2(CO) 6(μ-CO) 4(μ 4,η 2-HCCR)] (R=FeCp 2 1, CH 2OH 2, (CH 3O)C 10H 6CH(CH 3)COOCH 2CCH 3) and [RhCo 3(CO) 6(μ-CO) 4(μ 4,η 2-HCCR)] (R=FeCp 2 4, CH 2OH 5, (CH 3O)C 10H 6CH(CH 3)COOCH 2CCH 6) were obtained by the reactions of [Rh 2Co 2(CO) 12] and [RhCo 3(CO) 12] with substituted 1-alkyne ligands HCCR [R=FeCp 2 7, CH 2OH 8, (CH 3O)C 10H 6CH(CH 3) COOCH 2CCH 9] in n-hexane at room temperature, respectively. Alkynes insert into the Co---Co bond of the tetranuclear clusters to give butterfly clusters. [Rh 2Co 2(CO) 6(μ-CO) 4(μ 4,η 2-HCCFeCp 2)] (1) was characterized by a single-crystal X-ray diffraction analysis. Reactions of 1, 2 with 7, 8 and ambient pressure of carbon monoxide at 25 °C gave two known cluster complexes [Co 2(CO) 6(μ 2, η 2-HCCR)] (R=FeCp 2 10, CH 2OH 11), respectively. All clusters were characterized by element analysis, IR and 1H-NMR spectroscopy. 相似文献
13.
The P-functional organotin dichloride [Ph 2P(CH 2) 3] 2SnCl 2 (3) is synthesized by reaction of Ph 2P(CH 2) 3MgCl with SnCl 4 independently of the molar ratio of the starting compounds. The corresponding organotin trichlorides Ph 2P(CH 2) nSnCl 2R (4: n=2, R=Cl; 5: n=3, R=Cl; 6: n=3, R=Me) are formed in a cleavage reaction of Ph 2P(CH 2) nSnCy 3 ( n=2, 3) with SnCl 4 or MeSnCl 3, 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(Ph 3PO) 2 (7) and 5(Ph 3PO) (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
14.
The IR polarized spectra of gypsum CaSO 4·2H 2O were recorded at incidence angles of approximately 10 and 16 degrees. Band singlet or doublet was observed for the higher frequency ν 3(SO 42−) mode of Bu symmetry type, depending on polarization ( n or p). A doublet was observed for the lower frequency ν 3(SO 42−) mode of Bu symmetry type too, irrespectively of the type of polarization. In order to give an explanation for the doublets origin, a model permittivity function was constructed. Quite good agreement exists between the reflectance based on the model permittivity function and the experimentally measured one for the high-frequency doublet. The origin of the lower frequency doublet could not be explained in this way, but may be speculated to result from an Evans type interaction between a combination of a water libration and ν 2(SO 42−), with the lower frequency ν 3(SO 42−) mode. 相似文献
15.
The electron donating water soluble phosphines, P{(CH 2) nC 6H 4- p-SO 3Na} 3, n = 1, 2, 3 and 6, react rapidly with Co 2(CO) 8 under two phase reaction conditions to yield the disproportionation products, [Co(CO) 3(P{(CH 2) nC 6H 4- p-SO 3Na 3} 2] [Co(CO) 4]. Selective precipitation yields the formally zwitterionic complex anions as the sodium salt, [Co(CO) 3(P{(CH 2) nC 6H 4- p-SO 3} 3) 2] 5−. The anions can be used as precursors to water soluble cobalt hydroformylation catalysts under two phase and supported aqueous phase conditions. The tendency to form alcohol products is low with these complexes. The behavior of the catalysts is consistent with an active species that remains water soluble during the reaction and is not leached into the nonaqueous phase. 相似文献
16.
Lamellar crystalline calcium phenylphosphonate, as anhydrous Ca(HO 3PC 6H 5) 2 and hydrated Ca(HO 3PC 6H 5) 2·2H 2O compounds, were used as hosts for intercalation of polar n-alkylmonoamine molecules of the general formula CH 3(CH 2) nNH 2 ( n=0–4, 7) in water or 1,2-dichloroethane. An increase in the interlayer distance was observed. The exothermic enthalpic values for intercalation increased with the number of carbon atoms and with increasing concentration of the amines. The intercalation followed by a titration procedure in the solid/liquid interface with Ca(HO 3PC 6H 5) 2·2H 2O and Ca(HO 3PC 6H 5) 2 gave the enthalpy/number of carbons correlations: Δ intH=−(1.74±0.43)–(1.30±0.13) nc and Δ intH=−(4.15±0.15)–(1.07±0.03) nc, for water and 1,2-dichloroethane, respectively. A similar correlation Δ intH=−(4.27±0.80)–(1.85±0.21) nc was obtained in water by using the ampoule breaking procedure for Ca(HO 3PC 6H 5) 2·2H 2O. The increase in exothermic enthalpic values with the increase in n-aliphatic carbon atoms is more pronounced for the anhydrous compound and also when using the ampoule breaking procedure. The Gibbs free energies are negative. Positive entropic values favor intercalation in these systems. 相似文献
17.
Powder X-ray diffraction, 119Sn NMR spectra, and 1H NMR spin–lattice relaxation times, T1, were measured for (CH 3) nNH 4−nSnCl 3 ( n=1–4). From the Rietveld analysis, it is shown that all four compounds crystallize into deformed perovskite-type structures at room temperature. The temperature dependence of 1H T1 was analyzed in terms of the CH 3 reorientation and other motions of the whole cation. Except for the phase transition in CH 3NH 3SnCl 3, which is from monoclinic to rhombohedral at 331 K, 1H T1 was continuously changed at other phase transitions in this compound as well as in the n=2–4 compounds, suggesting that the transitions are not caused by the change of the motional state of the cation but by an instability of the [SnCl 3] nn− perovskite lattice. 相似文献
18.
We have previously determined an analytical ab initio six-dimensional potential energy surface for the HCl dimer, and in the present paper we use this potential, with the HCl bond lengths held fixed, in a full (four-dimensional) close-coupling calculation to determine the energies of the lowest 24 vibrational states. These vibrational states involve the intermolecular stretch ν 4, the trans-bend tunneling vibration ν 5, and the torsion ν 6. The highest of the 24 levels is the (ν 4ν 5ν 6)=(111) state, for which we calculate an energy of 200 cm −1 above the (000) state. As well as determining tunneling energies up to 5ν 5=183 cm −1, we determine ν 4=49 cm −1, 2ν 4=93 cm −1, 3ν 4=134 cm −1, 4ν 4=172 cm −1, ν 6=137 cm −1 and ν 4+ν 6=178 cm −1, together with tunneling energies in all these states. Making allowance for the HCl stretching zero-point energy we determine the dissociation energy D0 as 390 cm −1 on this analytical surface. We determine that below 300 cm −1 there are 72 vibrational ( J=K=0) states, and below dissociation there are 162 vibrational ( J=K=0) states, for this potential surface. 相似文献
19.
The vibrational spectrum of Sb 4O 6 in the gas phase has been measured at 1000 K by high-temperature infrared spectroscopy. The four infrared-active absorption bands were observed at ν 7 = 785.0 cm 1, ν 8 = 176.2 cm −1, ν 9 = 292.4 cm −1 and ν 10 = 415.6 cm −1. By combining these results with data on the molecular geometry and the infrared-inactive modes, as reported in the literature, the thermodynamic functions of Sb 4O 6 have been calculated. 相似文献
20.
Liquid—solid equilibrium temperatures are measured in binary mixtures of acetamide and inorganic salts [NaClO 4, LiCNS, LiNO 3, CH 3COOLi, Ca(NO 3) 2, (CH 3) 4 NCl, (C 2H 5) 4 NBr]. In some ranges of concentration all these systems (with the exception of CH 3COOLi, R 4NX) exhibit supercooling phenomena and crystallization occurs only through vigorous agitation and in the presence of crystalline nuclei, or does not occur at all, according to the type of salt. A probable explanation is presented on the basis of the trend of Δ T/ν mK vs. m. 相似文献
|