
TY  - JOUR
A1  - Hawkins, CJ 
A1  - Peachey, RM 
A1  - Szoredi, CL 
T1  - Conformational analysis of coordination compounds. VII. Barrier to inversion of five-membered diamine chelate rings by N.M.R
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1978
VL  - 31
IS  - 5
SP  - 973
EP  - 981
KW  - 
UR  - https://doi.org/10.1071/CH9780973 
N2  - The barriers to &#948; &#8596; &#955; interconversion for the five-membered diamine chelate rings in [M(CO)4(tmen)], where M is chromium(0), molybdenum(0), or tungsten(0) and tmen is N,N,N',N'-tetramethylethane-1,2-diamine, have been determined to be of the order of 39 kJ mol-1 from a band-shape analysis of 13C N.M.R. spectra of the compounds at low temperature. The results have been rationalized in terms of the effects of M-N bond lengths on ring strain energies and have been compared with the barriers determined previously for analogous complexes with coordination numbers of four (tetrahedral) and eight. The equivalent six-membered diamine chelate ring in [Mo(CO)4(tmtn)] was found to have a relatively low barrier to chair-to-chair interconversion with an upper limit of 34 kJ mol-1. 
ER  -

