{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T21:39:39Z","timestamp":1780695579948,"version":"3.54.1"},"reference-count":36,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,12,24]],"date-time":"2020-12-24T00:00:00Z","timestamp":1608768000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002383","name":"King Saud University","doi-asserted-by":"publisher","award":["RGP-0257"],"award-info":[{"award-number":["RGP-0257"]}],"id":[{"id":"10.13039\/501100002383","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>The gem-aminals of 1,2-dimorpholinoethane (1) and 1-morpholino-3-morpholinium bromide propane (2) were synthesized by reaction of two molar ratio of morpholine with the halogenating agents in the presence of basic condition (K2CO3) in acetone at room temperature (RT) overnight. The structures of the centro-symmetric compound 1 and the morpholinium salt derivative 2 were assigned unambiguous by single crystal X-ray diffraction analysis and compared with the 1,2-di(pyrrolidin-1-yl)ethane 3 and 1,2-di(piperidin-1-yl)ethane 4. The 1,2-dimorpholinoethane molecule has a center of symmetry at the midpoint of the C-C bond of the ethyl moiety leading to two equivalent halves. It crystallized in monoclinic crystal system and P21\/n space group, while the unit cell parameters are determined to be a = 6.0430(3), b = 8.0805(3), c = 11.1700(4) \u00c5, and \u03b2 = 97.475(2)\u00b0 with unit cell volume of 540.80(4) \u00c53 and Z = 2 at 170(2) K. The less symmetric analogue 2 crystallized in the lower space group P21 with unit cell parameters of a = 6.37450(10), b = 11.1378(2), c = 9.6549(2) \u00c5, and \u03b2 = 93.358(2)\u00b0, while the unit cell volume is 684.30(2)\u00c53 at 120(2) K. Using Hirshfeld analysis, the molecules of 1 are mainly packed by weak N\u2026H (4.2%), O\u2026H (16.8%), and H\u2026H (79.0%) interactions. In contrast, the molecules of 2 are packed by significantly short O\u2026H (14.4%) and Br\u2026H (11.6%) interactions in addition to the relatively long H\u2026H (73.3%) interactions. DFT calculations predicted the molecular geometry of the studied compounds showing a good agreement with the experimental X-ray structures. Due to symmetry considerations, compounds 1, 3, and 4 are nonpolar with zero dipole moment, while the less symmetric molecule 2 has a dipole moment of 6.914 Debye. Their electronic aspects, such as natural population charges, HOMO, and LUMO energies as well as the corresponding reactivity descriptors, were also calculated and discussed.<\/jats:p>","DOI":"10.3390\/sym13010020","type":"journal-article","created":{"date-parts":[[2020,12,24]],"date-time":"2020-12-24T22:56:45Z","timestamp":1608850605000},"page":"20","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["X-ray Crystal Structure and Hirshfeld Analysis of Gem-Aminals-Based Morpholine, Pyrrolidine, and Piperidine Moieties"],"prefix":"10.3390","volume":"13","author":[{"given":"Abdullah Mohammed","family":"Al-Majid","sequence":"first","affiliation":[{"name":"Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6744-7208","authenticated-orcid":false,"given":"Matti","family":"Haukka","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Jyv\u00e4skyl\u00e4, P.O. Box 35, FI-40014 Jyv\u00e4skyl\u00e4, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saied M.","family":"Soliman","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4112-1090","authenticated-orcid":false,"given":"Abdullah Saleh","family":"Alamary","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2720-2409","authenticated-orcid":false,"given":"Saeed","family":"Alshahrani","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Ali","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4612-5875","authenticated-orcid":false,"given":"Mohammad Shahidul","family":"Islam","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7885-3201","authenticated-orcid":false,"given":"Assem","family":"Barakat","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia"},{"name":"Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.catcom.2004.10.011","article-title":"Microwave accelerated preparation of [bmim][HSO4] ionic liquid: An acid catalyst for improved synthesis of coumarins","volume":"6","author":"Singh","year":"2005","journal-title":"Catal. 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