Zirconium fluoro complexes

Another preparative method in which the rate of precipitation is slow involves slow decomposition of zirconium fluoro complexes [14], These are first prepared by adding an appropriate amount of hydrofluoric acid (HF) to the zirconyl salt and these complexes are decomposed in the presence of phosphoric acid, with a slow stream of nitrogen or water vapor passing through the system. The rate of precipitation of zirconium phosphate is controlled by the rate of removal of HF from the system, and when this is very slow, a highly crystalline a-ZrP is obtained. The gamma form of the metal phosphate differs significantly from the alpha and current discussion will be concerned with the latter phase. 

ZnxZryFz. A fluoro complex of zirconium, ZrF62, and an ammine complex of zinc, ZnfNFF), have been used to grow ZnxZryFz films on silicon. The Zn/Zr/F ratio was 0.08/1/0.32, and the films contained hydroxyl groups and physisorbed water.128... 

Chloro- or bromocyclopentadienyl complexes of titanium and zirconium react with silver(I) tetrafluoroborate to form the corresponding fluoro complexes.81 Other complexes yielded the tetrafluoroborates. 

Zirconium metal (mp 1855°C 15°C), like titanium, is hard and corrosion resistant, resembling stainless steel in appearance. It is made by the Kroll process (Section 17-A-l). Hafnium metal (mp 2222°C 30°C) is similar. Like titanium, these metals are fairly resistant to acids, and they are best dissolved in HF where the formation of anionic fluoro complexes is important in the stabilization of the solutions. Zirconium will burn in air at high temperatures, reacting more rapidly with nitrogen than with oxygen, to give a mixture of nitride, oxide, and oxide nitride (Zr2ON2). 

Unit cell dimensions for the tetravalent protactinium fluoro complexes are listed in Table VIII. LiPaFs is a member of an isostructural series of 1 1 complexes formed by the actinide elements thorium to curium inclusive (91). Structural details are available for LiUP5 (5S), but bond distances have not been reported for the protactinium complex. The 7 6 complexes, like their actinide(IV) analogs (Th-Cm with Na, Th-Cm with K, and Th-Pu with Rb) are all 4, 114) isostructural with Na7Zr F3 (60) in which each zirconium atom is 8-coordinate and the... 

Erker et al. have shown that FAB adds to zirconocene (butadiene) complexes in toluene to yield zirconocene—(W-C4H6)—borate—betaine complexes (40, Scheme 14). A characteristic feature of the structure of 40 is the weak coordination of an ortho-fluoro substituent to the zirconium center to give a stable metallacyclic complex. This is a common structural... 

R. L. Davidovich, Stereochemistry of heteroligand fluoro-containing complex compounds of zirconium and hafnium, Russian J. Coord. Chem., 25, 225-236 (1999). 

---