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The IR, 13C- and 17O-NMR spectral characteristics of the Cr(CO)3 group in a series of eight chromium, tricarbonyl[3-[(η6-aryl)methylene]-Z-1(3H)-isobenzofuranones] were correlated mutually as well as with theoretical data obtained by optimized MMX force-field and EHT calculations. The net charges on the carbon and oxygen atoms of the CO group and their differences were found as the most appropriate quantitative characteristics for the electronic properties of the Cr(CO)3 group. Using the results of the previously reported linear correlations, the electron-withdrawing effect of the PhCr(CO)3 moiety, weakened by the back-donation effect, was estimated as σα≅0.45 on the scale of Hammett substituent constants.

The infrared and 13C NMR spectra and the kinetics of alkaline hydrolysis of chromium, tricarbonyl[3-[(η6-aryl)methylene]-Z-1(3H)-isobenzofuranones] have been studied in comparison with those of 3-arylmethylene-Z-1(3H)-isobenzofuranones. The 13C NMR spectroscopy has been found to be the most suitable tool for recognition of the site of complexation in the 3-arylmethylene-Z-1(3H)-isobenzofuranone system. A statistically significant correlation has been found between the arithmetic means of the wave numbers of symmetric and asymmetric stretching vibrations of Cr(CO)3 group and σp constants of the substituents. The large slope of this linear dependence suggests an important role of the mesomeric mechanism in the transmission of electronic effects to the Cr(CO)3 moiety. The strong electron-withdrawing effect of the Cr(CO)3 group causes a significant decrease of the polarity of the phthalide CO bond. The reaction rates of the alkaline hydrolytic ring-opening reaction dramatically increase due to the effect of Cr(CO)3 group. The absorption bands of the carbonyl stretching vibrations are markedly split due to Fermi resonance effect. After mathematical correction for Fermi resonance the wave numbers of the unperturbed fundamental CO stretching vibration and the log k values of alkaline hydrolysis exhibit significant linear correlations mutually, as well as with Hammett σ substituent constants. Charton's transmissive factors γ(PhCr(CO)3) have been determined for tricarbonylchromiumphenyl system using the parameters of the linear correlations. The efficiency of the substituent effect transmission is high in CCl4, because a back-donation effect of the carbonyl ligands and decreases in CHCl3 due to the hydrogen bonding between carbonyl groups and solvent molecules. The preparation of some novel chromium, tricarbonyl[3-[(η6-aryl)methylene]-Z-1(3H)- isobenzofuranones] is described.

Selectivity of complexation of substituted phenyl benzoates is very low. In most cases, comparable yields of both regioisomeric complexes are isolated. Exception is 4-chlorophenyl ester, where benzoic acid moiety is complexed nearly exclusively. Very high regioselectivity of complexation was observed with substituted phenyl phenylacetates. The substituent of substituted phenols has not any effect on the complexation, and only phenylacetic acid moiety is complexed. This observation supports the recently proposed mechanism of the catalytic activity of the esters at arene complexation.

The acid-catalysed complexation of various substituted phthalides with Cr(CO)6 has been studied. Complexation of substituted 3-benzylidene phthalides takes place at the phenyl ring in most cases, but with di-halogeno-substituted 3-benzylidene phthalides the complexation took place at the phthalide moiety. An explanation of this difference is based on molecular modelling quantum chemical calculations.

Hammett correlations between the CO stretching frequencies and substituent constants were studied for a series of 5-phenyl-2-thiophenecarboxaldehydes and 2-(5-phenyl-2-thenylidene)-1,3-indandiones and compared with those for a series of benzaldehydes and 2-benzylidene-1,3-indandiones. From the slopes of the statistically most significant relationships the transmissive factors for the thiophene ring in carbon tetrachloride and chloroform were calculated. Transmission by the thiophene ring is practically independent of solvent contrary to transmission by the furan ring, where the transmissive center interacts with solvent molecules. From a comparison of transmissive factors it was found that the efficiency of transmission by the bridging groups decreases in the order furan > thiophene > benzene i.e. in the order in which the delocalization energies of these systems increase. The preparation of nine new 2-(5-phenyl-2-thenylidene)-1,3-indandiones is also described.

IR spectra of one hundred and fifty-four 1,3-indandione derivatives representing various structural types have been measured in the CO stretching region. Linear relationships were found in three solvents between the symmetrical and asymmetrical CO stretching frequencies. The degree of vibrational coupling in the 1,3-indandione derivatives being compared with that in acyclic β-diketones. The influence of the structure of the compounds studied on the positions of the CO stretching bands as well as the validity of linear relationships between the symmetrical and asymmetrical CO stretching frequencies is discussed.

The reaction of salicylaldehyde, betaine and acetic anhydride gives 3-(N,N-dimethylamino)-2H-1-benzopyran-2-one in contrast with the published 2-(N,N-dimethylamino)-1,3-indandione.