Nickel axial single-crystal

Single crystals of [Ni(L56)(C2H50H)2](BF4)2 were isolated by recrystallisation of [Ni(L56)(CH30H)2](BF4)2 from ethanol. As their X-ray analysis revealed [26], nickel(II) pentagonal-bipyramidal coordination is realised in the complex via the five nitrogen atoms of L56 in the equatorial plane and the two ethanol molecules in the axial positions (Figure 2-2). 

Single-crystal ENDOR studies of the Ni-B state [83] showed two large nonexchangeable H HFCs that could be assigned to the methylene (CH2) protons of the bridging cysteine axially coordinated to die nickel (Fig. 1). This is in agreement... 

The vibrational spectrum of single-crystal Ni (0EP) C104 contained the marker band expected for an OEP species. Resonance Raman spectra were used to probe axial coordination and conformational heterogeneity of Ni(TPP) in the presence of nitrogenous bases. Similar experiments gave information on the protein-induced changes in non-planarity of the prophyrin in nickel cytochrome... 

A single-crystal X-ray study of the hydrazinium nickel oxalate dihydrate complex could not be carried out as the crystal shows twinning, rendering the X-ray investigation difficult. Therefore, based upon IR, UV spectra, and magnetic susceptibility data, the proposed structure of hydrazinium nickel oxalate dihydrate is represented as shown in Figure 5.9. In this case, apart from two bidentate (chelate), oxalate groups occupy the equatorial plane, while the axial positions are filled by hydrazinium cations. As a whole the nickel atom displays octahedral coordination. 

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