{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T00:34:05Z","timestamp":1700181245260},"reference-count":26,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2004,9,7]],"date-time":"2004-09-07T00:00:00Z","timestamp":1094515200000},"content-version":"vor","delay-in-days":3871,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Comput Chem"],"published-print":{"date-parts":[[1994,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p><jats:italic>Ab initio<\/jats:italic> MP2\/6\u201031G*\/\/MP2\/6\u201031G* and semiempirical AM1 and PM3 calculations on a series of differently substituted \u03b1\u2010oxo\u2010ketenes are used to investigate <jats:italic>E<\/jats:italic>\/<jats:italic>Z<\/jats:italic>\u2010isomerism and rotational barriers in these molecules. Sterically crowded derivatives are found to exist solely as s\u2010<jats:italic>E<\/jats:italic> conformers. The unusual stability of these derivatives thus can be attributed to their inability to adopt the s\u2010Z conformation required for the normal \u03b1\u2010oxo\u2010ketene reactions. With respect to structures and energies, the PM3 method (especially in the case of highly crowded molecules) is found to be less reliable than AM1. <jats:italic>Ab initio<\/jats:italic> HF\/3\u201021G and PM3 vibrational frequencies appear to be of sufficient accuracy for a distinction between s\u2010Z and s\u2010<jats:italic>E<\/jats:italic> conformers. In this respect, the AM1 method appears less reliable. \u00a9 1994 by John Wiley &amp; Sons, Inc.<\/jats:p>","DOI":"10.1002\/jcc.540150203","type":"journal-article","created":{"date-parts":[[2005,1,2]],"date-time":"2005-01-02T01:04:18Z","timestamp":1104627858000},"page":"132-143","source":"Crossref","is-referenced-by-count":13,"title":["Conformation and reactivity of \u03b1\u2010oxo\u2010ketenes: <i>Ab initio<\/i> and semiempirical (AM1, PM3) calculations"],"prefix":"10.1002","volume":"15","author":[{"given":"Rudolf","family":"Janoschek","sequence":"first","affiliation":[]},{"given":"Walter M. F.","family":"Fabian","sequence":"additional","affiliation":[]},{"given":"Gert","family":"Kollenz","sequence":"additional","affiliation":[]},{"given":"C.","family":"Oliver Kappe","sequence":"additional","affiliation":[]}],"member":"311","published-online":{"date-parts":[[2004,9,7]]},"reference":[{"key":"e_1_2_1_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/cber.19821150615"},{"key":"e_1_2_1_2_3","doi-asserted-by":"publisher","DOI":"10.1021\/jo00007a008"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/anie.198408021"},{"key":"e_1_2_1_3_3","doi-asserted-by":"publisher","DOI":"10.3891\/acta.chem.scand.46-0683"},{"key":"e_1_2_1_4_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00031a051"},{"key":"e_1_2_1_4_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.198408001"},{"key":"e_1_2_1_5_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00011a027"},{"key":"e_1_2_1_6_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00044a019"},{"key":"e_1_2_1_7_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00052a018"},{"key":"e_1_2_1_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4020(01)90376-X"},{"key":"e_1_2_1_9_2","doi-asserted-by":"publisher","DOI":"10.1002\/jcc.540130913"},{"key":"e_1_2_1_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar00177a002"},{"key":"e_1_2_1_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00016a014"},{"key":"e_1_2_1_11_3","doi-asserted-by":"crossref","first-page":"10981","DOI":"10.1021\/ja00053a056","volume":"114","author":"Zhao D.\u2010C.","year":"1992","journal-title":"J. Am. Chem. Soc."},{"key":"e_1_2_1_12_2","first-page":"1433","volume":"14","author":"Nikolaev V. A.","year":"1978","journal-title":"Zh. Org. Khim."},{"key":"e_1_2_1_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4039(00)60116-8"},{"key":"e_1_2_1_14_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00299a024"},{"key":"e_1_2_1_15_2","doi-asserted-by":"publisher","DOI":"10.1002\/jcc.540100208"},{"key":"e_1_2_1_16_2","doi-asserted-by":"publisher","DOI":"10.1002\/jcc.540090412"},{"key":"e_1_2_1_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/0166-1280(92)87023-S"},{"key":"e_1_2_1_17_3","doi-asserted-by":"publisher","DOI":"10.1021\/ma00006a012"},{"key":"e_1_2_1_18_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00297a049"},{"key":"e_1_2_1_19_2","unstructured":"VAMP: Erlangen Vectorized Molecular Orbital Package Version 4.40. A copy of a Stardent version of this program was kindly supplied by Dr. T. Clark Institut f\u00fcr Organische Chemie Universit\u00e4t Erlangen\u2010N\u00fcrnberg Germany."},{"key":"e_1_2_1_20_2","unstructured":"M. J. Frisch G. W. Trucks M. Head\u2010Gordon P. M. W. Gill M. W. Wong J. B. Foresman B. G. Johnson H. B. Schlegel M. A. Robb E. S. Replogle R. Gomperts J. L. Andres K. Raghavachari J. S. Binkley C. Gonzales R. L. Martin D. J. Fox D. J. Defrees J. Baker J. J. P. Stewart J. A. Pople 1992 Gaussian Inc. Pittsburgh PA"},{"key":"e_1_2_1_21_2","doi-asserted-by":"publisher","DOI":"10.1002\/jcc.540090414"},{"key":"e_1_2_1_22_2","doi-asserted-by":"publisher","DOI":"10.1002\/jcc.540120807"}],"container-title":["Journal of Computational Chemistry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fjcc.540150203","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/jcc.540150203","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,24]],"date-time":"2023-10-24T06:04:33Z","timestamp":1698127473000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/jcc.540150203"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,2]]},"references-count":26,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1994,2]]}},"alternative-id":["10.1002\/jcc.540150203"],"URL":"https:\/\/doi.org\/10.1002\/jcc.540150203","archive":["Portico"],"relation":{},"ISSN":["0192-8651","1096-987X"],"issn-type":[{"value":"0192-8651","type":"print"},{"value":"1096-987X","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,2]]}}}