Vibrational Spectroscopic Study of the Cocrystal Products Formed by Cinchona Alkaloids with 5-Nitrobarbituric Acid

Table 8

Assignments of the major bands in the fingerprint region of the Raman spectra of 5-nitrobarbituric acid, quinidine, and their 1 : 1 cocrystal product.

Assignment	Nitrobarbituric (cm^−1)	Cocrystal (cm^−1)	Quinidine (cm^−1)	Assignment
Carbonyl in-plane bending mode	379	365
Carbonyl out-of-plane bending mode	625	608
Carbonyl out-of-plane bending mode	695	681
N–H out-of-plane bending mode	846	836
C–N stretching mode	1150	1144
C–N deformation mode	1255	1243
		1362	1363	Nonprotonated quinuclidine mode
		1570	1561	Nonprotonated quinoline mode