The NO({:l) emission (B 'IT->X'II) observed during photolysis of N.O at 1470 A is due to a cherniluminescent reaction between N('D) and N.O. Transient measurements of this emission are analyzed to give the rate coefficients for removal of N (. D) by several simple molecules. Photolysis at 1236 A also produces NO(B 'IT), and the decay curves can be analyzed to give the same rate coefficients as observed at 1470 A, although there is evidence that an additional NO(B 'IT) production mechanism is involved. Quench'ng coefficients are also tabulated for N. (A 32;) and 0 (1 S), two other species investigated by the same technique.

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Experimental study of the reactions of N2(A 3Σ+ u ) with H atoms and OH radicals J. Chem. Phys. 95, 8866 (1991); 10.1063/1.461219 Statetostate N2(A 3Σ+ u ) energypooling reactions. I. The formation of N2(C 3Π u ) and the Herman infrared system J. Chem. Phys. 88, 231 (1988); 10.1063/1.454649 Mercury halide B(2Σ+) vibrational distributions from dissociative excitation reactions of Hg halides with Xe(3 P 2) and N2(A,3Σ+ u )The Vegard-Kaplan bands from N2(A 32;,,+)v'=O,1 were detected when highly purified, flowing N2 was subjected to a weak Tesla-type discharge. This excited state of Nt was destroyed when nitrogen atoms were added from an upstream microwave discharge. Measurements of the decay time of N2 (A 32;,,+), when the Tesla discharge was rapidly extinguished, gave indicating that the reaction was occurring with a rate coefficient of SXlO-11 cm 3 /sec.

Organic polymeric polyphosphonates adsorb on enamel surfaces in the form of a monolayer and inhibit calcium and fluoride ion transport but not that of phosphate ions. The polymers investigated include phosphonated polyethylene, polyvinylphosphonate, and polyvinylbenzylphosphonate. The adsorption of proteins on enamel, as exemplified by human serum albumin, is diminished and the adsorbed protein is more readily desorbed from surfaces with polymeric polyphosphonates. These findings may offer an explanation for the anticariogenic effect of polymeric polyphosphonates.The inhibitory effect of organic diphosphonates on crystallization and dissolution of hydroxyapatite in vitro and on bone metabolism in vivo has been demonstrated by Fleisch and others.1-4 Ethanehydroxydiphosphonate was shown to have caries-preventive activity5 parallel to a calculus-preventive action.6,7 Diphosphonates, however, exhibit a variety of physiological effects,8 some of them potentially detrimental9,"0; thus, their use as caries-or plaque-preventive agents warrants serious toxicologic considerations. Polymeric polyphosphonates are expected to be superior to diphosphonates and other "monomeric" oligophosphonates in preventing caries and dental calculus for a number of reasons. A polymeric molecule carrying many phosphonate groups is expected to interact with bone mineral more strongly because it can exchange phosphate ions on many calcium ions on the same crystallite. It is expected, therefore, that organic polyphospho-