Zinc phosphonate

A range of zinc phosphonates were prepared and structurally characterized by reaction of zinc nitrate with phosphonic acids in an autoclave in the presence of sodium hydroxide, including an enantiomerically pure zinc phosphonate—for example, Zn(03PCH2P(0)(C6H5)2) and Zn(0 3PCH2P(0)(CH 3)(C6H 5)). 40, 4°6... 

Attempts have been made to incorporate functional groups into the phosphonates in zinc phosphonate structures. Zn(03P(CH2)2C02H) H20 was reacted with aromatic amines but no amide formation was observed. However, Zn(03P(CH2)2C0NHC6H5) could be synthesized directly from zinc nitrate, (2-carboxyethyl)phosphonic acid, and aniline in a one-step procedure.406... 

Anhydrous zinc phosphonate Zn(03PCH3) is unreactive with water but reacts with primary amines (chain length up to Cg) and ammonia to form intercalation compounds. The intercalation is shape selective as amines with branching at the a-carbon cannot coordinate to the zinc. Different structures are noted for even and odd carbon chain lengths with odd numbers of carbons in the alkyl chain forming a more efficiently packed interdigitated structure.420... 

Organophosphonates are isoelectronic with organotrisiloxides. Like zinc siloxides and zinc siloxanes, zinc phosphonates are actively investigated as porous materials, for applications in catalysis, as molecular sieves, and for electronic devices. Dimethyl- and diethylzinc reacted with / //-butylphosphonic acid in THF solution to furnish,... 

In cooling systems where serious pitting corrosion can occur due to fouling by high levels of temporarily suspended solids or biomass (such as may be found, for example, in a steelwork), zinc phosphonate programs incorporating various dispersant polymers can be particularly successful. 

The success of stabilized phosphate programs, but mixed with growing concerns over phosphate levels in the environment, has resulted in the development of many programs with lower PO4 content but blended with various combinations of zinc, phosphonate, and polymers. 

One feasible method for the exploration of chiral open-framework compounds is the use of chiral chemical units as primary building blocks by coordinating with metal or other assembly methods to form 2-D layer or 3-D open-framework structures with optical activity. A notable example is the enantiomerically pure zinc phosphonate based on a mixed phosphonic acid-phosphine oxide chiral building block reported by Bujoli and coworkers in 2001.[91] The reaction procedures are shown as follows. 

This is the first reported enantiomerically pure zinc phosphonate with optical activity formed by the coordination of chiral building units, laying the foundation for further development of this method. 

F. Fredoueil, M. Evain, D. Massiot, M. Bujoli-Doeuff, and B. Bujoli, Enantiomerically Pure Zinc Phosphonates Based on Mixed Phosphonic Acid-phosphine Oxide Chiral Building Blocks. J. Mater. Chem., 2001, 11, 1106-1110. 

Zinc chromate + dispersant Zinc polyphosphate dispersant Zinc phosphonate + dispersant Phosphates h dispersants + organic inhibitors... 

Cooling water systems are one of the most important fields where synergistic corrosion inhibitor blends are applied for temporary corrosion protection. Several combinations have been developed which are capable of achieving increased protection under various plant operating conditions. Some of the most important synergistic mixtures are chromate-zinc, phosphonate-zinc, polyphosphate-zinc, polyphosphate-chromate, polyphosphate-phosphonate, and ni-trite-phosphonate. 

Fivizzani, K. P "Use of Molybdate as Corrosion Inhibitor in a Zinc/Phosphonate Cooling Water Treatment," U.S. Patent 5,320,779,1994. 

Zinc methylphosphonate intercalates aliphatic amines with no branching at the a-position, for example n- and o-butylamines the sec- and tert-butylamine isomers are excluded because of steric restriction by the mediylphosphonate group (13a). In the case of zinc phenylphosphonate (Hgure 2), access to the site vacated by the water molecule is sufficiently restricted that only ammonia is intercalated, and aliphatic amines are excluded (13b). The excellent shape-selectivity of these reactions suggests the possibility of making sensors for amines and ammonia from zinc phosphonates, provided the intercalation event can be transduced to an observable (electronic, optical, mechanical, etc.) signal. 

While the response of this device is rapid, the irreversibility of ammonia binding at room temperature places serious limitations on the use of zinc phosphonates in practical sensors. Another problem with devices derived from colloidal particles is the large external surface area, on which molecules other than the desired analyte can adsorb. This point is Ulustrated in Figure 4. Despite the fact that butylamine isomers are excluded from intercalation into bulk Zn(03PC6Hs), Ae mass change upon exposure of the device to either n- or tert-butylamine vapor is comparable to that found for ammonia. Adsorption of these interfering analytes is also quite slow, occurring over a period of hours. 

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