A solution and solid state study of niobium complexes University of ...

Chapter 4
Table 4.9: Hydrogen bonds for [NbCl(phacac-κ 2 -O,O’)(OMe)3] and [NbCl2(phacac-κ 2 -
O,O’)(OMe)2].
Interaction D-H···A D-H (Å) H···A (Å) D···A (Å) < D-H···A (°)
A C6 k , H6A k , Cl2 l 0.958 (3) 2.809 (6) 3.611 (8) 142.04 (4)
B C12 k , H12 k , O1 k 0.933 (4) 2.423 (2) 2.742 (6) 100.10 (3)
C C2 k , H2 k , Cl1 m 0.927 (3) 2.768 (4) 3.655 (5) 158.92 (6)
Symmetry operations: k [x, y, z]; l [x, 0.5-y, -0.5+z]; m [x, -0.5-y, 0.5+z]
Molecular packing within the unit cell (Figure 4.15) shows a “head to tail”
arrangement of the [NbCl(phacac-κ 2 -O,O’)(OMe)3] and [NbCl2(phacac-κ 2 -
O,O’)(OMe)2] complexes when viewed along the b-axis.
Figure 4.15: Complexes of [NbCl(phacac-κ 2 -O,O’)(OMe)3] and [NbCl2(phacac-κ 2 -O,O’)
(OMe)2] displaying a sheet-like “head to tail” crystal packing along the b-axis. Hydrogen
atoms have been omitted for clarity. Displacement ellipsoids are drawn at the 50%
probability displacement level.
The largest differential peak was 2.616 e.Å -3 , 0.93 Å from Nb1 and the deepest hole
-1.761 e.Å -3 , 0.80 Å from Nb1.
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