Neutron diffraction metal-oxygen bond distances

Finally, the configuration of the water (D20) molecule with respect to the metal ion can be probed by neutron diffraction methods. These give metal-deuterium distances which, when compared with metal-oxygen distances, give the angle between the plane of the water (D20) and the M—O bond. This is 55° for Nd3+ 193 it is said to vary with concentration for Ni2+ in solution.189... 

Thiosulphates and Thionates. A neutron-diffraction study has shown that in barium thiosulphate monohydrate the tetrahedral 8203 anion has the bond lengths S—8=1.979 and 8—0= 1.472-1.483 A the Ba—8 distances are 3.355 and 3.424 A. A crystal structure determination of bis(ethylenethiourea)zinc(ii) thiosulphate has shown that each zinc atom is tetrahedrally surrounded by three sulphur atoms (two from etu and one from the thiosulphate group, with the mean distance Zn—8 = 2.320 A) and one oxygen atom from the 82O3 group. Crystalline Zn(NH3)3(8203),H20 and Cd(NH3)3(8203) have been prepared and characterized spectral data indicate that the 8203 ion is unidentate and is bonded to the metal through sulphur. 

Bonds to Oxygen.—Compounds of Lower Oxidation State. The chemistry of hypophosphorous acid and the metal hypophosphites has been reviewed. Improved dimensions for the HPOaOH" ion have been reported in a neutron-diffraction investigation of the structure of LiH2P03 in particular, the P— distance has been revised to 1.396 A and the presence of strong hydrogen bonds defined. 

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