摘要:

AbstractMössbauer spectra are reported and discussed for a number of compounds of formula Fe(ligand)6(anion)2, with pyrazole, 3(5)‐methylpyrazole, imidazole,N‐methylimidazole andN‐n‐butylimidazole as ligands, and ClO4−, Br−and I−as anions.The values found for the isomer shift (δ) and the quadrupole splitting (ΔEq) are in agreement with high‐spin iron(II) in a distorted octahedral coordination.The magnitude of δ, being 1.32 ± 0.02 mm/s, in these compounds is rather small and occurs at the lower site of the range usually found for octahedral iron(II).For closely resembling compounds a relation is found between ΔEqand the value of the magnetic moment.The author is indebted to Drs.D. W. Engelfriet, D. Knetchand Ir.A. M. van der Kraanfor assistance with the measurements, and to Dr.A. M. van der Kraanfor assistance with the measurements, and to Dr.W. L. Groeneveldfor his i

ISSN:0165-0513    

DOI:10.1002/recl.19710901202

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractThe temperature dependence of the proton NMR‐spectra of bis(1,3‐diphenyl‐1,3‐propanedionato)Ni(II) and of bis(1,3‐di‐p‐tolyl‐1,3‐propanedionato)Ni(II) has been determined.We have interpreted the results using a model with two unpaired electrons per molecule. We conclude that the contact shifts of the various proton resonance signals result from delocalized unpaired electrons in the σ as well as the π sy

ISSN:0165-0513    

DOI:10.1002/recl.19710901203

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractDifferences in intramolecular shielding of the ester alkyl protons between rotamers in a series of alkylN‐(arylsulfonylmethyl)‐N‐methylcarbamates were used as an unambiguous tool for rotamer signal assignment. On the basis of these results, aromatic solvent‐induced shifts (Δv C 6D 6CDCl 3) and trifluoroacetic acid (TFA)‐induced shifts (Δv TFAC 6D 6) were found to be applicable as criteria for signal assignment of carbamate rotamers. Using these criteria, the conformations of previously unreported alkyl and arylN‐(alkylsulfonylmethyl)‐N‐methylcarbamates and arylN‐(arylsulfonylmethyl)‐N‐methylcarbamates have been determined. The rotamer population (E/Zratio) is discussed in terms of the structures of these carbamates. The smaller Δv TFAC 6D 6values of carbamates as compared with carboxamides are primarily the result of the lower ground state basicity of the carbamate function and of the presence of more than one site of comparable acceptor strength. This conclusion is supported by an IR spectroscopic study of hydrogen bond adduct formation between phenol

ISSN:0165-0513    

DOI:10.1002/recl.19710901204

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19710901205

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19710901206

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

Abstract(±)‐1,3‐Bis(2‐piperidyl)propan‐2‐one was resolved with the aid of the enantiomeric 6,6′‐dinitrobiphenyl‐2,2′‐dicarboxylic acids. Both optical rotatory dispersion measurements and chemical correlation showed thelaevo‐rotatory compound to be (‐)‐(R,R)‐1,3‐bis(2‐piper

ISSN:0165-0513    

DOI:10.1002/recl.19710901207

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19710901208

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19710901209

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractVapour phase chlorination of biphenyl in the temperature range 350‐450° leads to monochlorides with isomer distribution 35‐38%ortho, 47‐52%metaand 14‐16%para.This pattern is little temperature‐dependent. It is markedly different from that obtaining in liquid phase electrophilic chlorination as well as from the equilibrium distribution of monochlorobiphenyls, 53, 0, 47% and 3, 64, 33%, respectively. Thus as with other vapour phase halogenation patterns the isomer formed to the smallest extent in liquid phase electrophilic chlorination (meta) pr

ISSN:0165-0513    

DOI:10.1002/recl.19710901210

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19710901211

出版商:WILEY‐VCH Verlag    

年代:1971

数据来源: WILEY