ESTIMATION OF CONFORMATIONAL ENERGY OF COORDINATION-COMPOUNDS BY USING THE MODEL OF OVERLAPPING SPHERES

The newly proposed method for the estimation of conformational energy is based on the assumption that the sterical strain is proportional to the occupancy of the volume (defined by the sphere of radius R-vi) by the van der Waals spheres of the neighbouring atoms. The method was c hecked on planar copper(EI) bis- and aquabis-complexes with N-alkylate d amino acids, yielding the correlation coefficient between the confor mational energy and the sterical parameters up to r = 0.95. The propos ed method has been proved not to be very dependent on the exact geomet ry of the molecule or the calculation procedure, but it does not seem to be very reliable for small energy differences between the conformat ions (< 3-5 kJ mol(-1)). Its future application should, therefore, be viewed as a tool for an easy elimination of high-energy conformations.