Substituent effect on supramolecular motifs in series of succinimide polycyclic keto derivatives – Spectroscopic, theoretical and crystallographic studies Barbara Miroslaw a,⇑ , Anna E. Koziol a , Anna Bielenica b , Kamil Dziuba a , Marta Struga c a Faculty of Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland b Department of Biochemistry, Medical University of Warsaw, Warszawa 02-097, Poland c Department of Pharmacogenomics, Medical University of Warsaw, 02-007 Warszawa, Poland highlights  The substituent effect on supramolecular motifs in cyclic imides.  The sequence of carbonyl stretching vibration bands in IR spectra was determined.  The correlation between geometry and energetics of hydrogen bonds was analysed.  Solvation free energies were computed using IEF PCM model.  Binding energies for supramolecular clusters were calculated. graphical abstract article info Article history: Received 2 December 2013 Received in revised form 12 May 2014 Accepted 14 May 2014 Available online 28 May 2014 Keywords: Substituent effect Supramolecular synthon Hirshfeld surface analysis Solvation free energy PCM Binding energy abstract The substituent effect on the supramolecular arrangement in a series of polycyclic monoimide keto derivatives crystals was studied. Single crystal X-ray diffraction and IR spectroscopic experiments were performed for seven related compounds, as well as the Hirshfeld surface analysis and quantum chemical calculations at HF and DFT levels in vacuo, in solution and for small clusters. The presence of C@O group at the bridge of the main hydrocarbon skeleton implied the catemer motif of the N imide AHO imide hydrogen bond in case of smaller substituents (HA, MeOA, EtOA). For more voluminous groups ( i BuOA) or additional hydrogen bond acceptors (AcOA,O@) the steric hindrance increased and the imideimide interactions were no longer present in the solid state. The N imide AHO keto or N imide AHO ester hydrogen bonds were formed instead. The binding energy per one NAHO interaction calculated for supramolec- ular clusters at HF/6-31G(d,p) level was ca. 20 kJ mol 1 , indicating moderate strength of this hydrogen bond. The solvation free energies and induced dipole moments were computed at B3LYP/6-311+G(d,p) level using the integral equation formalism model (IEF PCM) considering three solvents of various polar- ity: non-polar chloroform, polar aprotic dimethyl sulfoxide (DMSO) and polar protic water. The relations between the vibrational spectra and the crystal structure have been discussed. The following sequence of carbonyl stretching modes in IR spectra has been derived from quantum chemical calculations: (1) at the highest frequencies – the symmetric vibration of two imide C@O bonds, (2) the vibrations of keto C@O bonds attached directly to the polycyclic hydrocarbon skeleton, (3) the asymmetric vibration of two imide C@O bonds, and (4) at the lowest frequencies – the vibration of ester C@O group. The characteristic http://dx.doi.org/10.1016/j.molstruc.2014.05.029 0022-2860/Ó 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Address: Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie-Sklodowska sq. 3, PL. 20-031 Lublin, Poland. Tel.: +48 81 5375582. E-mail address: barbara.miroslaw@umcs.lublin.pl (B. Miroslaw). Journal of Molecular Structure 1074 (2014) 695–702 Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstruc