Spectrophotometric study of 5-arylidene- and 5-(5-arylfurfurylidene)rhodanines

5-Arylidenerhodanines and the previously undescribed 5-5-(4-R-phenyl)furfurylidene]rhodanines were synthesized by the Andreasch method. It is assumed that Fermi resonance appears in the IR spectra of some of these compounds in the region of carbonyl absorption; bands of associated N-H bonds were identified. It is shown that in the case of 4-N(CH₃)₂-benzylidenerhodanine the long-wave band in the electronic spectra is a bathochromically shifted band of the same nature as the band in the spectra of 5-arylidenerhodanine derivatives with weak donor groups. The introduction of an arylfurfurylidene grouping gives rise to a substantial bathochromic shift of the absorption band of their molecules.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1490–1494, November, 1977.