title: Condensation reaction between carbohydrazide and salicylaldehyde: in-line vibrational spectroscopy monitoring and characterization of the reaction products in solution and solid state.
abstract: The condensation reaction between carbohydrazide and salicylaldehyde was monitored in-line by using vibrational NIR and Raman spectroscopies and statistical methods. Prior to in-line data analysis the reaction products were fully characterized in solution and solid state in order to check the potential of the in-line approach as a tool for in-process Schiff bases reaction control. It was demonstrated that a combination of vibrational spectroscopy and principal component analysis made it possible to detect and identify the reaction products, e.g. mono(salicylidene)carbohydrazide (1) and bis(salicylidene)carbohydrazide (2) in different solvents, and to determine the reaction end points in real time. Owing to complexity of the reaction mixtures and band overlapping, it was not possible to determine the relative ratio of the reaction products in-line. The off-line analysis showed that 1 was predominant in methanol while the highest portion of 2 was obtained in ethanol.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Jednačak
authors.forename: Predrag
authors.initials: P
authors.lastname: Novak
authors.forename: Aden
authors.initials: A
authors.lastname: Hodzic
authors.forename: Otto
authors.initials: O
authors.lastname: Scheibelhofer
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Khinast
authors.forename: Janez
authors.initials: J
authors.lastname: Plavec
authors.forename: Primož
authors.initials: P
authors.lastname: Sket
authors.forename: Vuković Jelena
authors.initials: VJ
authors.lastname: Parlov
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D053838:Scattering, Small Angle; D012996:Solutions; D013059:Spectrum Analysis, Raman; D014732:Vibration; D014961:X-Ray Diffraction
chemical_list: D000447:Aldehydes; D006834:Hydrazines; D012996:Solutions; C013243:salicylaldehyde; C019289:carbohydrazide