RESEARCH against rigidity. Spectroscopic evi dence and measurements of entropy of vaporization are consistent with this They can b e m a d e with rings up t o 3 4 members; show «ο view. T h e cyclic phosphonitrilies show a novel kind of arornaticrh' high degree of thermal and chemical stability. The Ρ—Χ bonds are short, strong, a n d equal in length. These ACS NATIONAL MEETING facts strongly suggest aromatic charac ter. This aroinaticily, however, must be of Λ different type than that found in the benzene series, With carhoovclic compounds only six-membered rings The longest inorganic homologOTJS can be aromatic. But with the phos series so far known, a 34-membered i n phonitrilies, aromatic rings of almost organic ring, a new type of aromatiiuty any size apparently can be formed. —these are some of the results of m e r i t T h e difference here appears to be in studies of the phosphonitrilic fluoridl-es the way in which the aromatic bonds and chlorides. are formed, says Paddock, in benzene, In the fluoride series, cyclic polyme-rs the C—C bonds are formed by the over of the type (PN T F 2 )„ have been pre lapping of the ρ orhitals of the carbon pared, separated, and characterized u p atoms. I n the phosphonitrilies, the to η = 17. These large ring fhioricl*es Ρ—Ν b o n d s are formed by the overlap are s\nthesized by way of the corre ping of t h e ρ orhitals of the nitrogen sponding chlorides, according to N. ~L·, atoms with the d orhitals of the phos Paddock of Albright & Wilson, Ltd., phorus atoms. The result is a new type England. Paddock told the Division of of aromatieity which has not been ob Inorganic Chemistry at the Symposium served before. on Phosphorus Chemistry he and bris coworkers let phosphorus pentaehloiicie / / ι Synthetic Proteins" react with ammonium chloride to get a mixture of cyclic polymers. These (Nan Approach Nature's be separated by distillation up through the octamer. Natural proteins almost du They then fluorinate the mulistillal^lc plicated by Florida re residue with potassium fluorosulfite to searchers; vast potentials get a mixture of volatile phosphonitrilic loom ahead fluorides which can be separated Tby vapor phase chromatography. From the pentamer upward these cyclic fluo ACS NATIONAL MEETING rides are mobile liquids which ratlier N. L. Paddock resemble the fluorocarbons in some . cyclic and flexible Biological Chemistry properties. They are relatively inert chemically, and they have very low Very close to nature's own proteins boiling points for their molecular is the w a y to describe the "synthetic weights. proteins" developed at Florida State Evidence for the cyclic structure of University. These synthetic materials these fluorides is primarily twofold: /, .-χ,:. -·;.-·ί- .rîai,·. were m a d e by polymerizing all 18 of / ' Λ : ^ . ^ \ ώ . 'Ρ • The lower members of the fluori de the common amino acids; they could $ι M*I itr.s a i t ; n u t d c ιΓΟϊΤι CmOnCicS W n i o h ijiwviuc-:
