RESEARCH FC Ν Chemistry Opens New Fields Researchers look at fluorocarbon nitrogen chemis try for clues to high strength and chemical resistance HILE hydrocarbons most often de compose by breaking carbon-hydrogen bonds, fluorocarbons apparendy de compose by breaking carbon-carbon, not carbon-fluorine, bonds. The strength of the C—F bond is believed to be a major cause of the good chemi cal and thermal resistance of fluorocar bons. Might still more interesting com pounds result with still stronger bonds? Seeling a possible answer, researchers are now studying the «carbon-nitrogen bonds in fluorocarbon nitrogen com pounds. An indication of the possibilities of such compounds is CF 3 N=MCF 3 , which is untouched by elemental fluorine up to 500° C. Its resistance to further re action with fluorine is vastly better than that of C—Ν and Ν—Μ bonds in organic molecules. What of the other possibilities? Comparatively little is; known of the preparation and reactions o f even the simplest possible compounds containing fluorine and nitrogen-euorocarbon amines. John A. Young or the Univer sity of Florida says that systematic fluorocarbon nitrogen chemistry is still in its toddling stages. Present knowl edge shows anything from complete correlation to complete discrepancy with classical organic nitrogen chemis try. Developing a systematic chemis try of fluorocarbon nitrogen, derivatives would serve to open a whole field of new synthetic materials, says Young, and it will add to our understanding of organic nitrogen reaction mechanism. Two series of fluorocarbon com pounds are possible-emther fluorine re placing hydrogen in the alkyl groups only or throughout the molecule. Be cause two kinds of hydrogen exist in primary and secondary amines (amine hydrogen and alkyl hydrogen), am biguities are possible i n connoting these compounds simply ^.s fluorocarbon amines. For -want of a better name, Young suggests calling the completely substituted compounds ' nitrides." Organic amines R3N R2NH RNH 2 Fluorocarbon amines ( R F ) 3 N (RF)2NHE RFNH 2 3872
C&EN
A C S . 13,
NH3 NHS
1956
"Nitrides" (RF)3N
(RF)2NF
RFNF 2
NF3
(RF refers to alkyl group with hydro gen atoms replaced by fluorine.) • Via Electrochemistry, Classic organic amine preparation involves either reducing a more oxidized nitro gen compound or nitrogen atom alkylation. Neither of these methods works for fluorocarbon amines or nitrides. Such compounds as fluorocarbon nitriles (RFCN) are reduceable, but they go to a 1,1-dihydro amine of the type RFCH 2 NH 2 , not a true fluoro carbon amine, according to Young. At present, the best way to make fluorocarbon amines and nitrides seems to be by an electrochemical process. Low-voltage current is passed through a solution of a particular organic amine in anhydrous hydrofluoric acid to make the tertiary compounds. The first
member of the series, ( C F 3 ) S N is diffi cult to make by electrolysis, but Minne sota Mining and Manufacturing makes the inert perfluoro tribiatyl compound— (CaF^sN—commercially b y this elec trochemical process. Both secondary amines and second ary nitrides must be made indirectly. Carbamyl chlorides and H F in an elec trochemical process substitute fluorine atoms for hydrogen and chlorine atoms. Heating drives out COF 2 ; further reac tion with HF or fluorine produces either the fluorocarbon amine or nitride: (CH 3 ) 2 NCOCl
H F
600° C. CF,N=CFo
HF 150°
CF.N=CF.>
F>
> (CF3KNCOF e C F 3 N = C F 2 + COF 2 (CF3)2NH (CF3)2NF
So far, this procedure works best for methyl derivatives; longer chain car bamyl chlorides form heterocyclic rings whose structure is difficult to elucidate. Considerable doubt exists, r~ys Young, that primary fluorocarbon amines will ever be reported because of probable instability which would prevent isolation. He bases his con clusion on secondary amines which readily lose H F with slightest traces of water. Primary fluorocarbon nitrides such as CF 3 NF 2 can be made, along
Research at National Cash Register National Cash Register's $5 million engineering research center, to b e completed in June, will provide greatly expanded facilities for all phases of business machine development. Included in the center's activities will be research on n e w types of solid-state electronic devices, new magnetic materials, ferroelectric materials, high speed printing principles, and electroluminescent phenomena. Also, fundamental research will be conducted in electrochemistry, colloid, and physical chemistry, along with work in application of radioisotopes to new products and processes.
PRODUCING
SYNTHETIC ORGANICS? TENNESSEE
CORPORATION
ara content exceptionally high
otal Toluene Sulfonic Add 96% or above
uperior physical form. Completely liquid above 80° F, nhydrous, too! P a r a Toluene Sulfonic A c i d , A nhydrous. ORGANIC CHEMICALS
TENNESSEE
DIVISION
C 0 RΡ0 RATION
617*29 Grant Building, Atlanta, Georgia
AUG.
13. 19 5 6 C & E N
3873
RESEARCH
Fluorometric Analysis For r a p i d precise analysis o f compounds f £ susceptible to fluorometric measurement » . . j Vitamins. Quinine. Atabrine, Porphyrins, Steroids and metal complexes. S e n s i t i v e ta» l o w i n t e n s i t y f l u o r e s c e n c e and to low concentrations. A C o p e r a t e d , no-drift circmît. O n l y 3 simple controls* direct r e a d i n g . . . Only $420.00. Ask for: "Coleman fools for Science,'1 contains useful discussions of nephelometry and other mod> era analytical technics. ^^J
fâm^ii
with perfluoro azomethane and perfluoro hydrazine derivatives, by direct fluorination of methylaniines; however, the reaction is difficult to control and yields are poor. To date no convenient or systematic preparation has been developed for the series of primary fluorocarbon nitrogen compounds. • Fluorocarbon Amides· Simple amides of fluorocarbon acids are very easily made, even more easily than amides of organic acids. Researchers first thought that primary fluorocarbon amines might be obtained from primary fluorocarbon amides in much the same way organic amines are obtained from organic amides—using the Hofmann degradation reaction. Extensive investigation showed Hofmann degradation reaction products from fluorocarbon amides to be halides, hydrides* isocyanates or coupled fluorocarbon groups, rather than amines. The actual product depends on fluorocarbon amide's chain length and the hypohalite used:
Coleman Photofluoromefer
Organic amide: RCONH 2 + NaOX
> RNH2
Dept. C, Coleman Instruments, Inc., Maywood, III.
Fluorocarbon amide: CF3CONH0 + NaOX
> CFfcCF3
C F 3 ( C F 2 ) 2 C O N H 2 + NaOBr > CF 3 CF 2 CF 2 Br Organic chemîstslknowjnn Qferaaentists» hexagon;n
CF 3 (CF 2 ) 2 CONHU 4- NaOI — • CF 3 CF 2 CF 2 rI
w%mm^mhMm^j^mr[BmM^MmMn ominmmkm^i^m^mm^^^^nn Ant»nea!kfleciditi€f?«nonuf
