{"corpus_id":96764972,"paper_sha":"b49f1c26ac69d0ab0528bc6589c17dec3c156c62","doi":"10.1515/znb-2007-0410","arxiv_id":null,"pmid":null,"pmcid":null,"mag_id":2056323015,"dblp_id":null,"acl_id":null,"title":"Studies of Dihydropyridines by X-Ray Diffraction and Solid State 13C NMR","year":2007,"publication_date":null,"venue":"","journal":{"name":"Zeitschrift für Naturforschung B","pages":"549 - 555","volume":"62"},"journal_issn":null,"journal_title":null,"publication_types":[],"pubmed_pub_types":null,"s2_fields_of_study":["Chemistry"],"reference_count":3,"citation_count":8,"influential_citation_count":0,"is_open_access":false,"arxiv_categories":null,"arxiv_license":null,"arxiv_journal_ref":null,"mesh_headings":null,"chemicals":null,"comments_corrections":null,"source_flags":1,"s2_open_access_pdf_url":null,"s2_open_access_landing_url":null,"s2_open_access_license":null,"s2_open_access_status":null,"pmc_open_access_pdf_url":null,"pmc_open_access_landing_url":null,"pmc_open_access_license":null,"pmc_open_access_status":null,"unpaywall_open_access_pdf_url":null,"unpaywall_open_access_landing_url":null,"unpaywall_open_access_license":null,"unpaywall_open_access_status":null,"abstract":"Fourteen dimethyl 4-aryl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates (DHPs) were evaluated by means of single crystal X-ray diffraction in order to investigate the effects of the structure in the crystals on the solid state 13C NMR chemical shifts. These include the analysis of three DHPs containing two molecules per asymmetric unit. The chiral rotamer unit generated by the s-cis/s-trans orientation of the carbonyl groups, as well as by rotation of the 4-phenyl ring out of the bisecting plane containing the N1, C4, C7 atoms, resulted in a significant magnetic non-equivalence for the C2-CH3/C6-CH3 and the COOCH3 pairs of signals. The solid state 13C NMR data reveal that the substitution pattern of the phenyl ring has a marked effect on the extent to which the signals of the carbonyl carbon atoms and those of C-2/C-6 peaks are split.","claims":[{"public_id":"cl_5a15dd49b0689b0852f6aea4a3d79b55","status":"active","text":"Phenyl-ring substitution pattern markedly affects the splitting of the carbonyl carbon and C-2/C-6 signals in the solid-state 13C NMR spectra.","confidence":0.96,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_5a15dd49b0689b0852f6aea4a3d79b55"},{"public_id":"cl_2f6c07493298d213cef185969d65e035","status":"active","text":"Single-crystal X-ray diffraction of fourteen dimethyl 4-aryl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates was used to relate crystal structure to solid-state 13C NMR chemical shifts.","confidence":0.98,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_2f6c07493298d213cef185969d65e035"},{"public_id":"cl_feede233ef7f4092f2f44eb378ee1036","status":"active","text":"The chiral rotamer unit created by s-cis/s-trans carbonyl orientation and rotation of the 4-phenyl ring produces significant magnetic non-equivalence in the C2-CH3/C6-CH3 and COOCH3 signal pairs.","confidence":0.97,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_feede233ef7f4092f2f44eb378ee1036"},{"public_id":"cl_3e2b0068d550716d7520eca62b27b191","status":"active","text":"Three of the DHPs contained two molecules per asymmetric 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