摘要:

Crystals of bis[methyltris(1-pyrazolyl)gallato]nickel(II) are rhombohedral,a = 9.6670(5),c = 23.893(1) Å,Z = 3, space group. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a finalRof 0.030 andRw = 0.035 for 925 reflections withI ≥ 3σ (I). The crystal structure consists of well separated molecules of [MeGa-(N2C3H3)3]2Ni having exact(S6) symmetry and approximateD3dsymmetry. The coordination geometry about the nickel atom is octahedral with Ni—N = 2.109(2) Å, N—Ni—N = 90.65(6) and 89.35(6)°. The gallium atom has distorted tetrahedral coordination geometry with Ga—N = 1.939(2), Ga—C = 1.940(4) Å, N—Ga—N = 99.55(6), and N—Ga—C = 118.16(5)°.

ISSN:0008-4042    

DOI:10.1139/v79-290

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

In Part I (Mol. Phys.35, 1681 (1978)) we used results from the Xα scattered wave (XαSW) method for guiding the parametrisation of the complete neglect of differential overlap (CNDO) method for clusters of silver, and we proposed the extension of this approach to other heavier elements for which CNDO schemes are not well developed. The main purpose of the present paper is to test this approach for the elements aluminium to sulphur for which more information is available. XαSW calculations have been made for the molecular clusters Al7, Si5H12, and P4, and comparisons made with experiment and with other calculations where possible. The charge distributions and transition-state energies, along with information obtained previously for S8by Salahubet al., have been used to derive new parameters (designated CNDO/HM) for the elements aluminium to sulphur essentially following the procedure in Part I. Calculations using these parameters have then been tested against an XαSW calculation made here for an Al10cluster (which simulates the (111) surface of aluminium), and against other calculations made previously for P8, P4S3, SiH4, PH3, H2S, and SO2. Comparisons are also made with results from the CNDO/2 scheme. Generally the CNDO/HM procedure seems at least as successful as CNDO/2.

ISSN:0008-4042    

DOI:10.1139/v79-291

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Potential curves are reported for the ground and various valence and Rydberg excited states of HOCl and HClO usingabinitioSCF and CI methods. The states of HOCl are found to be generally favored over their counterparts in HClO, but the calculations indicate that small barriers nevertheless exist for angular interconversion between at least some pairs of such states; they also show that dissociation processes involving ClO bond breaking are universally favored for both HOCl and HClO. Additional calculations for the ions have also been carried out, from which the heat of formation of HOCl+is calculated to be 237 kcal/mol and it is pointed out that a previous estimate for the corresponding HOCl quantity has subsequently been substantiated by experiment; the relative energies of the first four states of HOCl+are found to be in good agreement with experiment as well.

ISSN:0008-4042    

DOI:10.1139/v79-292

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Various 5,9b-dihydrobenz[e]indolines were synthesized by three general methods: (a) by alkylation with the appropriate alkyl halide of 1,2,4,5-tetrahydro-1H-benz[e]indoles, themselves obtained by alkylation with bromochloroethane of enamines derived from 7-alkoxy-2- tetralones; (b) from 1-alkylaminoethyl-2,2-ethylenedioxy-1,2,3,4-tetrahydronaphthalenes by acid hydrolysis, and (c) by reduction of 2-oxo-2,3,5,9b-tetrahydro-1H-benz[e]indoles which in turn were obtained from ethyl 2-oxo-1,2,3,4-tetrahydro-1-naphthalene acetates by reaction with methylamine followed by dehydration. These substances are key intermediates in the synthesis of 9-oxobenzomorphans.

ISSN:0008-4042    

DOI:10.1139/v79-293

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The synthesis of 5-allyl-2′-methoxy-2-methyl-9-oxo-, 2′-methoxy-2,5-dimethyl-9-oxo-, 5-allyl-2-cyclopropylmethyl-2′-methoxy-9-oxo-, and 5-(3-ethylenedioxy)butyl-2′-methoxy-3-methyl-9-oxo-6,7-benzomorphans (5a–d) by an improved process is described. It involves bromination of the 5,9b-dihydrobenz[e]indolines to the bromoiminium bromides, followed by hydrolysis with ammonium bicarbonate which converted them to 4-bromo-5,9b-dihydro-benz[e]indolines (in a fast step). These underwent hydration (in a slow step) followed by rearrangement to5a–d. The course of these reactions was different when sodium, potassium, and ammonium hydroxides were substituted for ammonium bicarbonate.

ISSN:0008-4042    

DOI:10.1139/v79-294

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

5-Allyl-2-cyclobutylmethyl-2′-methoxy-, 5-allyl-2′-benzyloxy-2-methyl-, 5-benzyl-2′-methoxy-2-methyl-, and 5-allyl-2′-benzyloxy-2-cyclobutylmethyl-9-oxo-6,7-benzomorphans were prepared by a previously described process. The process involves bromination of the 5,9b-dihydrobenz[e]indolines to β-bromoiminium bromides followed by treatment with a weak base in aqueous organic solvents. Ammonium bicarbonate and aluminium oxide are effective bases for the conversions of the β-bromoiminium salts to 9-oxobenzomorphans5a–g. The mechanism of the reaction involves formation of the bromoenamines (fast step) followed by hydration of the latter (slow step) and rearrangement to5a–g.

ISSN:0008-4042    

DOI:10.1139/v79-295

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Reaction ofN,N′-diethoxycarbonyl-2,5-dideoxystreptamine (1b) with thionyl chloride produced the iminoether dihydrochloride8which, upon simple treatment with water gave the di-N,O-carbonyl compound9. Acidic hydrolysis of9yielded the aminocyclitol2a. Alternatively,2awas prepared fromN,N′-dibenzoyl-2,5-dideoxystreptamine (1c) via the oxazoline10followed by acidic hydrolysis. Treatment of1cwith triethyl orthoacetate in the presence of boron trifluoride etherate produced the oxazoline11and the latter product was hydrolyzed to give3a. By the same reaction sequence,1eand1hwere converted to the oxazolines12and13which upon acidic hydrolysis provided the enantiomeric aminocyclitols4and5. Ring-opening reactions ofcis- andtrans-1,4-diepoxycyclohexanes (14and16) with sodium azide to the diazido compounds15and17, followed by reduction, afforded the aminocyclitols6and7.

ISSN:0008-4042    

DOI:10.1139/v79-296

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The spin–spin coupling between the proton and the fluorine nuclei,2J, in fluoroform varies by 1% in a range of solvents. It is argued that2Jdecreases algebraically as the van der Waals solute–solvent interactions increase in magnitude. Such a decrease is also observed for coupling constants which likely contain a substantial positive orbital contribution. If the van der Waals interactions perturb the spin–orbital term inJ, then2Jin fluoroform may well contain orbital contributions, as recently calculated for2Jin methyl fluoride. In that event, the large discrepancies between observed2J(H,F) values and those calculated by semiempirical theories of the contact term may be partially attributed to the neglect of orbital terms.

ISSN:0008-4042    

DOI:10.1139/v79-297

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The long-range spin–spin coupling constants over six bonds,6JpH,CH, in 3,5-dibromodiphenylmethane and 4,4′-difluorodiphenylmethane, respectively, imply that the ground state conformations of these molecules haveC2vsymmetry (gable conformations). In terms of a hindered rotor model which assumes a twofold barrier to internal rotation about the exocyclic carbon–carbon bond, the barrier in the dibromo derivatives is 1.1 ± 0.3 kcal/mol. A satisfactory fit to the temperature dependence of6JpF,CHis found for a gable conformation. If the conformational properties of these molecules and of diphenylmethane are determined mainly by steric interactions betweenorthoC—H bonds on neighbouring phenyl groups, it seems likely that the results above are a first approximation to the conformational behaviour of diphenylmethane. Some molecular orbital calculations are in semiquantitative agreement with the conclusions based on coupling constants.

ISSN:0008-4042    

DOI:10.1139/v79-298

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Tetraethylammonium fluoride in dimethylformamide promotes the alkylation of phenols with alkyl iodides and benzyl chloride to provide good yields of alkyl phenyl ethers. A number of phenols have been investigated including examples of sterically hindered phenols, phenols containing anion stabilising groups, and intramolecularly hydrogen bonded phenols, the majority of which react smoothly and efficiently in the fluoride system.

ISSN:0008-4042    

DOI:10.1139/v79-299

出版商:NRC Research Press    

年代:1979

数据来源: NRC