Crystal Structure of a Coumarin-Indoline Hybrid Dye

Abstract

In this paper we report on the crystal structure of 4-methyl-4′,5′-dihydropyrrolocoumarin (MDPC, see Figs. 1 and 2). The tricyclic chromophore is formed on ring-closure by bridging amino nitrogen (N(1)) and ring carbon (C(6)) with two methylene groups (C(7) and C(8)). The tricyclic compound is regarded as a coumarin-indoline hybrid in which a pyrrolidine moiety is condensed with a coumarin skeleton.A previous spectroscopic study 1 suggests that the methylene bridge makes the amino moiety more pyramidal than simple Nalkylation without ring formation. Pyramidalization at the nitrogen atom may be responsible for the observed blue shift and the slight decrease in the molar extinction coefficient or oscillator strength in comparison with the more planar Nalkylaminocoumarin. 1 MDPC was synthesized according to a procedure described by Quanten et al. X-ray Structure Analysis Online Crystal Structure of a Coumarin-Indoline Hybrid DyeNoriko KITAMURA,* Yoshiharu TORIUMI,** Shigeru KOHTANI,* , *** and Ryoichi NAKAGAKI* , *** † *Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan **Toray Research Center, Inc, 3-3-7 Sonoyama, Otsu 520-8567, Japan ***Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan The crystal structure of 4-methyl-4′,5′-dihydropyrrolocoumarin (MDPC) has been determined by X-ray diffraction. The crystal, C12H11NO2, belongs to space group P21/c with cell dimensions of a = 7.539(2)Å, b = 19.230(2)Å, c = 6.9395(9)Å, β = 103.89(1)˚. The final R value is 0.036. The methylene bridge in the indoline moiety makes the amino moiety more pyramidal than simple N-alkylation.

Ethyl esters of coumarin-3-phosphonic acid and 1,2-benzoxaphosphorine-3-carboxylic acid: crystal structure, spectroscopic and theoretical elucidation

“…Similar to other derivatives [15,16], the latter result indicates a co-linear disposition of the transition moments for the out-of-plane modes (a 00 ) (Scheme 3). The calculated geometrical parameters, bond lengths and angles correlated well with experimental values for other coumarins, as previously determined by single crystal X-ray diffraction [26][27][28][29][30] and for the reported crystal structure of 2. Differences of less than 0.1002 Å and 3.2(1)°are observed.…”

New Cyclodextrin‐Bearing 8‐Hydroxyquinoline Ligands as Multifunctional Molecules

“…The copper(II) and zinc(II) complexes of 4 have been also characterized and the coordination of metal ion by N, phenolate O, and COO À groups has been reported. [42,43] From the data reported in Table 1, it is interesting to note that the presence of the CyD does not decrease the affinity of 8-OHQ moiety for the metal ion. In these ligands, in addition to donor atoms of quinoline moiety, other potential donor atoms can be identified.…”

“…[49] These findings are characteristic of the OHQ derivatives when the complexation is accompanied by the deprotonation of the hydroxyl group. [50] For comparison with similar systems [42,45,51] and, in keeping with the stability constant values, a main species in which the metal ion is bound to the N of the pyridyl ring, phenolate, amino group, and deA C H T U N G T R E N N U N G pro-A C H T U N G T R E N N U N G tonA C H T U N G T R E N N U N G ated amide nitrogen can be hypothesized.…”