Density functional theory (DFT) investigations of title organometallic compounds led to identification of electronic features which determine the magnitude and the orientation of the dipole moment. The analysis of our theoretical results shows that the presence of a strong acidic BF3 group, or more generally, the substitution of ligands in the M(CO)(x)ClyL complexes can affect the orientation of the dipole moments, out of the direction of the first charge transfer (CT) excitation and, as a consequence, the magnitude of the vector part of the second order hyperpolarizabilities. (C) 2003 Elsevier Science B.V. All rights reserved.