摘要:

AbstractRehybridization as a possible means to alleviate the effects of sterical hindrance and ringstrain has been investigated. This concept, although general in nature, has been analysed in detail for ethylenic structures. It is shown that two out of the six fundamental distortions of a“molecule” can be counter‐balanced by rehybridization. One of these, the in‐plane rehybridization of thesp2hybrid orbitals, seems to be the most useful mechanism. For small distortions the change inpcharacter (as given by its mixing coefficient λk) for each of thesesp2orbits depends only on the change in bond angle (ΘY) opposite to the (k) hybrid orbital. It is shown that Δλk= √6ΔΘY.The theory allows the prediction of infrared frequency shifts for the  C‐H stretching, C  C stretching, C  C‐H in‐plane deformation, and C  C‐H out‐of‐plane deformation vibrations as a function of sterical hindrance. A comparison of the infrared spectra of a large variety of ethylenic hydrocarbons reveals a very satisfactory agreement be

ISSN:0165-0513    

DOI:10.1002/recl.19650840102

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe infrared spectra of a number ofcis‐ andtrans‐benzal ketones have been recorded. The carbonyl stretching frequencies can be understood by taking into account the occurrence of rotational isomerism. The spectra ofcis‐benzal acetones suggest that these compounds occur predominantly in one conform

ISSN:0165-0513    

DOI:10.1002/recl.19650840103

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe synthesis of a series of arylsulfonyl chlorides by a modification of the Sandmeyer reaction as developed byMeerweinet al1is described. This method seems applicable to the preparation of arylsulfonyl bromides, but not for arylsulfonyl fluorides. The characteristic IR vibrations of the SO2‐group are tabulated for the various arylsulfonyl halide

ISSN:0165-0513    

DOI:10.1002/recl.19650840104

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

Abstract2‐Alkynyl ethers of the types R′R″CH‐CC‐CH2OC2H5and R′R″R″′C‐CC‐CH2OC2H5(in which R′, R″ and R″′ are alkyl groups) have been converted by means of sodamide in liquid ammonia, in 70‐95% yields, into the allenyl ethers R′R″CH  C  CH‐OC2H5and R′R″R″′C‐CH  C  CH‐OC2H5.Acid hydro

ISSN:0165-0513    

DOI:10.1002/recl.19650840105

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe influence of oxygen on the number of individual particles in 10−3· 10−2molar diethyl ether solutions of ethylmagnesium bromide, diethylmagnesium, magnesium bromide and a mixture of diethylmagnesium and magnesium bromide was investigated. The ethoxide formed from the ethylmagnesium compounds is present as a tr

ISSN:0165-0513    

DOI:10.1002/recl.19650840106

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe title products can be prepared readily from triphenylplumbyl‐lithium and carbon tetrachloride, chloroform or methylene chloride. The existence of (Ph3Pb)4C is remarkable from a stereochemical point of vie

ISSN:0165-0513    

DOI:10.1002/recl.19650840107

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractA number of metastable peaks in the mass spectra of methyl acetate, propionate, butyrate, valerate and hexanoate were investigated. By measuring the kinetic energy of the ions of those peaks 28 degradation reactions of the esters were determined.

ISSN:0165-0513    

DOI:10.1002/recl.19650840108

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractReactions of 3‐bromo‐4‐ethoxypyridine and 2‐bromo‐6‐ethoxypyridine with lithium piperidide in piperidine have been investigated.It was found that in these compounds both substituents when occupying positions 2,4 or 6 are replaced by the piperidino group without rearrangements occurring. From 3‐bromo‐4‐ethoxypyridine some 2,4‐dipiperidinopyridine is formed as an additional product, probablyvia4‐piperidino‐2,3‐py

ISSN:0165-0513    

DOI:10.1002/recl.19650840109

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractA new convenient procedure is reported for the titration of ceric sulfate with sodium oxalate at room temperature. The procedure consists in the titration of ceric sulfate with sodium oxalate in about 0.5Nnitric, perchloric, or hydrochloric acid media, using nitroferroin as indicator.

ISSN:0165-0513    

DOI:10.1002/recl.19650840110

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractA rapid and convenient volumetric method is reported for the estimation of chromium (VI) and vanadium (V) in mixtures. The procedure consists in the estimation of (1) chromiumplusvanadium in the mixture by titration of the mixture in about 0.25Nsulfuric acid containing 5 ml of phosphoric acid and 1 ml of 0.1% barium diphenylamine sulfonate with ferrous ammonium sulfate to the exact end‐point; (2) vanadium in the mixture by titration of the solution, left after the first titration, with permanganate, using ferroin as indicator, and (3) chromium in the mixture by calculation from the difference of the two value

ISSN:0165-0513    

DOI:10.1002/recl.19650840111

出版商:WILEY‐VCH Verlag    

年代:1965

数据来源: WILEY