| Abstract
| - By analogy with dimolybdenum compounds, analyzed before, it is shown that a simple relationship between bond order, harmonic force constant, and characteristic bond length can be obtained by comparison of molecular mechanics solution curves for dichromium bonds of different order. The relationship, interpreted as a sampling curve, provides a useful classification of compounds in terms of effective bond order as a basis for discussing the influence of bridging groups and axial ligands on the dichromium bond length.
- Compounds containing dichromium bonds have been modeled in comparison with related dimolybdenum systemsby molecular mechanics, in order to establish a sampling curve that reflects the functional relationship betweencharacteristic bond length, ro, harmonic force constant, kr, and bond order, N, for all. Intersection of thesampling curve with any molecular-mechanics solution curve {kr, ro}, for dichromium compounds identifies aneffective bond order for the Cr−Cr bond. By this approach the known flexibility of dichromium bonds of constantformal bond order was analyzed, and it was shown that the effective bond order is not a function of electroncount only but also relates sensitively to both axial and equatorial ligation.
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