Research output: Contribution to journal › Article › peer-review
A series of 2,5-dibromo-3-R-thiophenes (R = COONa 1, CN 2, CONH2 3, CON(H)Me 4, CON(H)Bn 5, CON(CH2CH2)2O 6, CON(H)NH2 7, CON(H)OH 8) were prepared and studied via high-resolution ESI-MS, 1H and 13C{H} NMR, IR, and X-ray diffraction. The analysis of the X-ray structures revealed Br···Br halogen bonds (XBs) as structure-directing interactions. A search of the Cambridge Structural Database showed an additional 12 structures of 2,5-dibromothiophenes whose structures featured Br···Br XBs. The crystal packing patterns for all these 2,5-dibromothiophenes were classified, and three general types were identified: (i) chains held by XBs, where each Br acts either as an XB donor or as an XB acceptor; (ii) zigzag arrays, where each Br functions simultaneously as an XB donor and acceptor; and (iii) rhombic assemblies with Br atoms at each vertex. DFT calculations, followed by topological analyses of the electron density distribution (QTAIM analysis) at the M06-2X/DZP-DKH level of theory, were performed to evaluate the strength of these XBs. The established energies were in the range from 0.5 to 2.2 kcal/mol, regardless of the packing type.
Original language | English |
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Pages (from-to) | 2526–2540 |
Number of pages | 15 |
Journal | Crystal Growth and Design |
Volume | 21 |
Issue number | 4 |
DOIs | |
State | Published - 7 Apr 2021 |
ID: 76378409