Tetragonal bipyramid

Wade also incorporates electron-rich species such as C5H5 and C4H42- as arachno species derived by removal of two nonadjacent high-coordination vertices from the pentagonal and tetragonal bipyramids, respectively, and has, moreover, correlated many aspects of seemingly unrelated classes of compounds beyond the recognized borders of carborane chemistry. 

Further confirmation of the structure comes from the X-ray crystal structure analysis of the cyclopropylcarbinyl tungsten complex CpW(CO)3(C5FI9) which reveals a tetragonal bipyramidal geometry at the metal, and a typical bisected conformation of the cyclo-propylcarbinyl-M moiety. The sigma C—M bond distance of 234 pm is expectedly much longer than the W—CO bonds (115 pm). 

Spin admixed case, anisotropic [elongated tetragonal bipyramid of Fe(III), S = 5/2]... 

Case 2 Compressed tetragonal bipyramid. The ground term 2 g is orbitally degenerate. 

Fig. 17 Modeling the magnetic functions (level-6) for a nearly-octahedral Ti(III) complex F4(xy) = 5000 cm 1, F4(z) = 6000 cm 1 (compressed tetragonal bipyramid) dot-dashed -the parallel (z) component, dashed - the perpendicular (xy) component, solid - averaged. Right extrapolated temperature independent paramagnetism - dashed...

For an elongated tetragonal bipyramid (axial weakening) the following... 

Case 3 Compressed tetragonal bipyramid, large Aax X - the ground orbital singlet 3A2g is well separated, excitations calculated within the 3Tig and 3r2g patterns. gz = ge... 

Case 4 Compressed tetragonal bipyramid, small Aax X - the ground orbital singlet interacts considerably with excited states and needs a solution of the 9x9 secular equation (which is factored) yielding efA) = 2.[- v/3 + Akx (v2 + 2Atczv + A2(/c2 + 8k2))1/2]/2 ... 

The magnetism is little affected by the excited states A and A, and their presence is reflected in a considerable TIP (> 100). With the stronger CF asymmetry the TIP value decreases visibly. The -factor in the parallel direction, gz = ge, is constant for the entire range of the compressed tetragonal bipyramid. In the perpendicular direction it significantly decreases when the octahedral geometry is approached (Fig. 32). 

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