Bond recent neutron diffraction studies

Recent Neutron Diffraction Studies of Metal-Hydrogen-Metal Bonds... 

West [23] reported that TIN3 is isomorphous with KN3 with the unit-cell dimensions a = 6.21 and c = 7.37 A. Recently Muller [19] investigated the structure of TIN3 by X-ray diffraction and obtained N-N = 1.16(24) and Tl-N = 3.04(3) A. A recent neutron-diffraction study [7] revealed that the Nj ions undergo very large librational motion, not only at room temperature but also at lower temperature (260°K). The N-N bonds, corrected for librations, were 1.181(4) A for the room temperature and 1.184(1) A for the 260°K structure. Recently Mauer et al. [24] have studied the phase transitions of TIN3 by X-ray... 

Another deeply investigated system is that of Ti-MFI (or Ti silicalite) [255]. Only a very small amount of Ti actually enters the silicalite structure in normal tetrahedral sites, although some of them can be bonded to hydroxy groups in open defects [256]. Anatase-like extraframework Ti oxide particles are formed when excess titanium is present upon the preparation. The presence of Ti makes Ti-silicalite less defective than pure silicalite and also changes its room temperature structure from monoclinic to orthorombic. A recent neutron diffraction study showed that Ti sitting is preferential on the sites where defects are frequently present in pure silicalite [257]. 

Aqueous solutions of nickel(II) salts in the absence of strong coordinating species are usually green because of the [Ni(H20)ft]2+ cation.1447 The number of coordinated water molecules in the inner-shell complex is now well ascertained in the temperature range -30 to 30 °C by means of electronic and both 170 and LHNMR spectra.1448-1451 The most recent value of the coordination number is 5.85 0.2.145 Neutron diffraction studies of NiCl2 in D20 solution led to estimates of the Ni—O bond distance within the [Ni(D20)6]2+ cation in the range 195-220 pm.1452 A second hydration sphere of about 15 water molecules has also been proposed. 

When spectroscopic evidence for the existence of C60 was first obtained, a view prevailed that it would be a very unreactive molecule. This conclusion was based on the assumption that with a possible 12500 resonance structures (Klein et al. 1986), C60 would be superaromatic. However, the earlier molecular orbital calculations (Bochvar G alpern 1973) correctly predicted that there would be substantial bond fixation in the molecule more recently, the bond lengths have been determined by neutron diffraction studies to be 1.391 A and 1.455 A (David et al. 1991) other methods give similar values. 

Olovsson I, Jdnsson PG (1976) X-ray and neutron diffraction studies of hydrogen bonded systems. Chap 8. The hydrogen bond - recent developments in theory and experiments. Schuster P (ed). North-Holland, Amsterdam, pp 393-456... 

Several other recent crystallographic evidences of H-H bonding interactions have also appeared in the literature. For example, Pozzi et al.[55] conducted a 100 K single crystal neutron diffraction study of a methoxylated derivative of... 

---