594-20-7Relevant academic research and scientific papers
Far infra-red absorption of disubstituted propanes in rotator, solid and liquid phases
Haffmans,Larkin
, p. 1729 - 1741 (1972)
Experimental observations of the far infra-red (f.i.-r.) absorption spectra of three polar di-substituted propanes (2,2-dichloro-, 2-chloro-2-nitro-, 2-methyl-2-nitro-propane) over the temperature range 133-303 K in the liquid, rotator and non-rotator solid phases are reported. The spectra in both the liquid and rotator phases are discussed in terms of two simple theoretical models of librational and relaxational motions: an acceptable fit to the experimental spectra is obtained on the basis of reasonable barriers and other parameters of the molecular motion. One of the models indicates that the molecular librational potential wells may become narrower with decreasing temperature and that there may be a distribution of potential well depths or shapes. The variation of potential barrier height with group substitution is also discussed.
The interaction of molybdenum pentachloride with carbonyl compounds
Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
, p. 2477 - 2487 (2013/03/29)
The reactions of MoCl5, 1, with small amounts of a series of carbonyl compounds in a chlorinated solvent were investigated. The chloroiminium salts [ClCHNEt2][Mo(O)Cl4{OC(H)NEt2}], 2a, and [ClCNH(CH2)4CH2][Mo(O)Cl 4{OCNH(CH2)4CH2}], 2b, were obtained by a selective 1:2 molar reaction of 1 with, respectively, N,N-diethylformamide or ε-caprolactam. Otherwise 1 reacted with tetra-N-alkyl ureas in a 1:2 ratio to give the Mo(iv) mononuclear complexes MoCl4(urea) 2 [urea = (Me2N)2CO, 3a; urea = (Et 2N)2CO, 3b; urea = (EtPhN)2CO, 3c] in high yields. Addition of 2 equiv. of ketones to 1 resulted in clean formation of equimolar amounts of MoOCl3(OCR2) (R = Me, 4a; R = Et, 4b; R = Ph, 4c) and R2CCl2. Analogously 1,2-C 6H4(Me)(CHCl2) was produced from MoCl 5 and ortho-tolyaldehyde. The reactions of 1 with 1H-indole-2,3-dione (isatin) took place with selective chlorination of the carbonyl function non-adjacent to the nitrogen: the complexes MoOCl3(3,3-dichloro-2,3- dihydro-1H-indol-2-one)2, 5a, and MoOCl3(isatin)(3,3- dichloro-2,3-dihydro-1H-indol-2-one), 5b, were isolated depending on the stoichiometry employed. The X-ray molecular structures of 2b, 3b, 4b, 5a and 5b were ascertained.
A crystallographic and spectroscopic study on the reactions of WCl 6 with carbonyl compounds
Dolci, Sara,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
, p. 5635 - 5648 (2013/06/05)
WCl6, 1, reacted with two equivalents of HC(O)NR2 (R = Me, Et) in CH2Cl2 to afford the W(vi) oxo-derivatives WOCl4(OCHNR2) (R = Me, 2a; R = Et, 2b) as main products. The hexachlorotungstate(v) salts [{OC-N(Me)CH2CH2CH 2}2(μ-H)][WCl6], 3, and [PhNHC(Me)N(Ph)C(O) Me][WCl6], 4, were isolated in moderate yields from the 1:2 molar reactions of 1 with N-methyl-2-pyrrolidone (in CH2Cl2) and acetanilide (in CDCl3), respectively. The additions of two equivalents of ketones/aldehydes to 1/CH2Cl2 yielded the complexes WOCl4[OC(R)(R′)] (R = Me, R′ = Ph, 5a; R = R′ = Ph, 5b; R = R′ = Me, 5c; R = R′ = Et, 5d; R = H, R′ = 2-Me-C6H4, 5e) and equimolar amounts of C(R)(R′)Cl2. Analogously, WOCl3[κ2- {1,2-C6H4(O)(CHO)}], 5f, and 1,2-C6H 4(OH)(CHCl2) were obtained from 1 and salicylaldehyde. The 1:1 reaction of 1 with acetone in CH2Cl2 resulted in the clean formation of WOCl4 and 2,2-dichloropropane. Compounds 5a,b,f were isolated as crystalline solids, whereas 5c,d,e could be detected by solution NMR only. The interaction of 1/CH2Cl2 with isatin, in a 1:1 molar ratio, revealed to be a new, convenient route for the synthesis of 3,3-dichloro-2,3-dihydro-1H-indol-2-one, 6. The 1:1 reactions of 1 with R′OCH(R)CO2Me (R = H, R′ = Me; R = Me, R′ = H) in a chlorinated solvent afforded the tungsten(v) adducts WCl 4[κ2-OCH(R)CO2Me] (R = H, 7a; R = Me, 7b). 1/CH2Cl2 reacted sluggishly with equimolar quantities of trans-(CO2Et)CHCH(CO2Et) and CH2(CO 2Me)2 to give, respectively, the W(iv) derivatives WCl4[κ2-CH2(CO2Me) 2], 8a, and [WCl4-κ2-{trans-(CO 2Et)CHCH (CO2Et)}]n, 8b, in about 70% yields. The molecular structures of 2a, 3, 4, 5a, 5f, 7a and 7b were ascertained by X-ray diffraction studies.
ROLE OF INTERMOLECULAR INTERACTIONS IN THE SELECTIVE EFECT OF THE MEDIUM ON FREE-RADICAL CHLORINATION
Aver'yanow, V. A.,Golubev, V. E.,Semenov, A. O.,Kostylev, I. M.
, p. 1759 - 1764 (2007/10/02)
The effect of noncomplexing solvents on the selectivity of the free-radical chlorination of 2-chloropropane was studied.It was shown that the relative reactivity of C-H bonds in 2-chloropropane correlates with the solubility parameter and with the Kirkwood function.The obtained data are treated as a result of solvation of the chlorine atoms in solution.It was concluded that it is necessary to include the contribution from the substrates to the overall effect of the medium during interpretation of the selective action of the complexing solvents.
EFFECT OF THE COMPLEX-FORMING CHARACTERISTICS OF AROMATIC SOLVENTS ON THE SELECTIVITY OF FREE-RADICAL CHLORINATION. CHLORINATION OF 2-CHLOROPROPANE
Aver'yanov, V. A.,Ruban, S. G.
, p. 1119 - 1125 (2007/10/02)
During investigation of the effect of six solvents of aromatic nature on the selectivity of the free-radical chlorination of 2-chloropropane it was found that the / ratio insceases with increase in the content of the solvent in the reaction mixture and with decrease in the temperature.The obtained data were interpreted by a mechanism involving the formation of ? complexes between the chlorine atoms and the aromatic molecules ArHCl. as particles responsible for the selective effect of the solvents.On the basis of the adopted mechanism an equation was obtained for the selectivity of the process with parameters reflecting the relative reactivities of the various C-H bonds in the 2-chloropropane during their reaction with the chlorine atoms and the ArHCl. complexes.The differences in the activation energies of the competing reactions of the C-H bonds with ArHCl. correlate with the electron-donating characteristics of the solvent molecules.
EFFECT OF ACETIC ACID ON THE SELECTIVITY OF FREE-RADICAL CHLORINATION PROCESSES
Aver'yanov, V. A.,Ruban, S. G.
, p. 2267 - 2269 (2007/10/02)
The effect of acetic acid on the selectivity of the chlorination of 1,1-dichloroethane and 2-chloropropane in the range of temperatures between -10 and 60 deg C was investigated.It was shown that increase in the acetic concentration leads to a decrease in the amount of products from chlorination at the chlorine-substituted position, and in the region of high solvent concentrations the selectivity of chlorination becomes insensitive to temperature.The results are discussed from the standpoint of the increase in the steric and energy hindrances during attack at the more substituted positions due to the solvatation of the chlorine atoms and the substrate molecules.
Thermocatalytic Reactions of Bromochloropropanes
Levanova, S. V.,Rodova, R. M.,Tereshkina, T. P.,Zabrodina, T. I.
, p. 1142 - 1146 (2007/10/02)
The thermodynamic characteristics of the disproportionation and dehydrohalogenation reactions of halogenopropanes (1,2- and 2,2-isomers) have been calculated and tested experimentally.The legitimacy of using the incremental method for the calculation of the thermodynamic functions of bromochloropropanes has been demonstrated.An increase of the length of the hydrocarbon group and the geminal positions of the halogen atoms in the molecule greatly reduce the probability of disproportionation reactions.
EFFECT OF o-DICHLOROBENZENE ON SELECTIVITY IN THE CHLORINATION OF CHLOROPROPANES
Aver'yanov, V. A.,Zarytovskii, V. M.,Shvets, V. F.
, p. 1487 - 1491 (2007/10/02)
The competing chlorination of chloropropanes in o-dichlorobenzene was investigated over a wide range of temperatures and o-dichlorobenzene concentrations.The selective action of o-dichlorobenzene is interpreted by a mechanism involving attack on the C - H bond in the chloropropanes by free chlorine atoms and by aromatic ? complexes ArH -> Cl.Mathematical models of the selectivity of the processes based on the proposed mechanism were obtained.The parameters of the models reflect the relative reactivity of the C - H bonds during chlorination by chlorine atoms and ArH-> Cl complexes and also the capacity of the solvent for complex formation with chlorine atoms.
Carbon-13 NMR Spectra of Polybromoalkanes and Polychlorobromoalkanes. Structural Increments of Halogens in Polyhalogenated Groups
Dostovalova, V. I.,Velichko, F. K.,Vasil'eva, T. T.,Kruglova, N. V.,Freidlina, R. Kh.
, p. 251 - 260 (2007/10/02)
The 13C NMR spectra of 48 polychlorobromoalkanes have been studied.Unlike, the 13C signals of chlorine-containing groups (38-105 ppm), those of bromine-containing fragments, with the exception of CBr2 (60-70 ppm), appear in a rather narrow range (25-50 ppm) and are shifted to higher field in relation to similar chlorine-containing groups.The spin-spin coupling constants in similar bromine- and chlorine-containing groups practically coincide.Calculation of the chemical shifts for the polyhaloalkanes under study according to the additivity scheme, as previously observed for polychloroalkanes, renders values which are in considerable discord with experimental values (up to -32 ppm for CBr3).These discrepancies may be compensated for by corrections for the binary interaction of halogen atoms by grouping the halogen-containing fragments according to the geminal, vicinal, 1,3-, 1,3,5- and 1,2,3-arrangement of halogen atoms, and by introducing an increment for the position of the halogen at the secondary atom.It is established that as compared to 1-monohaloalkanes: (a) in the case of the geminal arrangement of halogen atoms the α- and γ-effects diminish (Δα from -3.2 to -8 ppm; Δγ=2.6 ppm), while the β-effect increases slightly (from 0 to 1.2 ppm); (b) in the case of a vicinal arrangement both the α- and β-effects diminish (by about -3.5 ppm) and the γ-effect remains constant, as if the vicinal system of the halogens was topologically insulated; (c) for the 1,3- and 1,3,5-arrangement of halogens their mutual influence is weak (about -0.5 ppm for each halogen atom in the α- and γ-positions); (d) the 1,2,3 system (serial arrangement of halogen atoms) is the sum of two vicinal fragments and hardly deviates from the additivity scheme; (e) the arrangement of a halogen at the secondary C atom enhances the α-effect (Δα=2.8 and 1.0 for methyl and methylene, respectively, in the case of Cl, and 3.5 and 3.7 ppm in the case of Br); the variation of the β-effect has a different sign in relation to CH3 and CH2 groups (+1.2 and -1.7 for Cl, and +2.5 and -1.0 for Br).More distant effects of halogens (δ and ε) were not considered.The determined increments (Δα, Δβ and Δγ) for the α-, β- and γ-effects of chlorine and bromine atoms allow the prediction of the 13C chemical shifts in polyhaloalkanes with an accuracy up to +/-1.5 ppm.Some deviations of up to +/-5 ppm may be connected with the influence of a three particle interaction of halogen atoms, which was taken into account only in the case of a geminal arrangement of halogen atoms.
