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Carbon‐13/carbon‐12 isotope effects on 119 Sn nuclear shielding
Author(s) -
Kerschl Susanna,
Sebald Angelika,
Wrackmeyer Bernd
Publication year - 1985
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260230706
Subject(s) - chemistry , tin , electromagnetic shielding , atom (system on chip) , kinetic isotope effect , carbon fibers , isotope , isotopomers , carbon atom , silanes , crystallography , molecule , deuterium , atomic physics , organic chemistry , alkyl , nuclear physics , silane , physics , materials science , composite number , computer science , electrical engineering , composite material , embedded system , engineering
Secondary 13 C/ 12 C isotope effects (Δδ i ) over one bond on the 119 Sn nuclear shielding have been determined for 42 organotin compounds. Changes in the magnitude and sign of Δδ i are related to the nature of the carbon atom and the nature of the other substituents at the tin atom. In addition to the rotational and vibrational effects connected with the Sn 13 C bond itself, Δδ i is affected by the bonding of tin to the other substituents. In the case of polar bonds this leads to deshielding of the tin atom in the heavy isotopomer, which compensates the shielding effect normally associated with heavy isotopic substitution. Therefore, the magnitude of Δδ i values and of the SnC bond distances are not related in a simple manner. A relationship exists between J ( 119 Sn 13 C) and Δδ i in alkynyltin compounds. The Δδ i ( 13 C/ 12 C) values for 29 Si and 207 Pb shielding in some representative organo‐silanes and ‐plumbanes are reported for comparison.