PM3(tm) analysis of transition-metal complexes

Transition-metal complexes with prototypical ligands were studied using the PM3(tm) semiempirical method. The calculated complexes in this paper inclu de 35 halides, 7 aqua complexes, 7 tris(ethylenediamine) complexes, 27 mult iply bonded complexes, and 19 organometallics. PMS(tm)-predicted geometries were compared with the experimental data from 1200 crystal structures. For multiply bonded complexes, a comparison was also made between PM3(tm) and higher level calculations employing effective core potentials and MP2 wave functions. In general, PM3(tm) was quite successful in predicting the geome tries of transition-metal complexes, especially those incorporating metals from the left-hand side of the transition series.