molbank Short Note 1,3-Bis{[(E)-(9-ethyl-9H -carbazol-3-yl)methylene] amino}propan-2-ol Ismail Warad 1, *, Nisreen Amer 1 , Huda Abedalrazeq 1 , Anas Al Ali 1 ID , Nabil Al-Zaqri 2 , Hicham Elmsellem 3 and Abdelkader Zarrouk 3 1 Department of Chemistry, An-Najah National University, P.O. Box 7, Nablus 0097, Palestine; nisreena135@hotmail.com (N.A.); huda123razeq@gmail.com (H.A.); anas.alali@najah.edu (A.A.A.) 2 Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; nalzaqri@ksu.edu.sa 3 LCAE-URAC18, Faculty of Sciences Oujda, University of Mohammed Premier, BP 4808, Oujda 60046, Morocco; h.elmsellem@yahoo.fr (H.E.); azarrouk@gmail.com (A.Z.) * Correspondence: warad@najah.edu; Tel./Fax: +970-9234-5982 Received: 22 February 2018; Accepted: 5 March 2018; Published: 7 March 2018 Abstract: Condensation of 1,3-diaminopropan-2-ol with 9-ethyl-9H-carbazole-3-carbaldehyde in absolute ethanol under stirring condition resulted in the formation of 1,3-bis{[(E)-(9-ethyl-9H- carbazol-3-yl)methylidene]amino}propan-2-ol within 0.5 in an excellent yield. The structure of the desired Schiff base was physically analyzed via CHN-elemental analysis, TOF-MS, UV-vis, FT-IR, and 1 H& 13 C-NMR. Computational studies of the structure were performed at the DFT/B3LYP/6-311++G(d) level of theory. Molecular electrostatic potential (MEP), Mulliken charge, IR-B3LYP,and structure optimization were performed. Keywords: DFT; Schiff base; complexing agent; condensation; optimization 1. Introduction Schiff base (SB) (>C=N-) preparation, reported first by Hugo Schiff (1915–1834) [1], is considered a broad branch in the organic field of natural science. Compounds containing azomethine functional group compounds are usually prepared by condensation of primary amines (-NH 2 ) with aldehyde (R(=O)H) or ketone (R(=O)R’) carbonyl compounds [2,3]. Considerable biological activity in antifungal, anti-apoptotic, anti-inflammatory, antiviral, and antibiotic agents has been documented for the above-mentioned compounds [4]. Beyond this, these compounds are of interest for their electroluminescent [5] and fluorescence properties [6] and hold promise as sensors [7], corrosion inhibitors [8], organic photovoltaic materials [9], and catalysts [10]. Due to the lone pair electrons on nitrogen, SBs are considered good metal complexing agents. Mono-, bi-, and poly-dentate complexing agents suitable for transition metal coordination via >C=N–, improving the complexes’ physicochemical, pharmacological, and catalytic properties [11–15]. Regardless of the number of SB ligands and their complexes, there remains a need for new SBs and SB complexes with novel properties for new applications. In connection with previous work [2,16–18], 1,3-bis{[(E)-(9-ethyl-9H-carbazol-3-yl)methylidene]amino}propan-2-ol was prepared and analyzed, spectrally and DFT-computationally, in this study. 2. Results 1,3-Bis{[(E)-(9-ethyl-9H-carbazol-3-yl)methylene]amino}propan-2-ol was synthesized by condensing 2.2 equiv of 9-ethyl-9H-carbazole-3-carbaldehyde with 1 equiv 1,3-diaminopropan-2-ol in absolute ethanol under stirring conditions, as shown in Scheme 1. Within 0.5 h at room temperature (23 ◦ C), Molbank 2018, 2018, M986; doi:10.3390/M986 www.mdpi.com/journal/molbank