title: Relationships between structure and carbonyl stretching frequencies of the beta-lactam ring and the 7-acylamino group in 1-thia- and 1-oxa-cephem antibiotics. Importance of the bending angle of the C(4)-N(5) bond from plane C(6)-N(5)-C(8) in the beta-lactam ring.
mesh_terms: D002511:Cephalosporins; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
chemical_list: D002511:Cephalosporins