NOTES 1693

TABLE IV

Molecular weight and conductance results of CoC12.3L*

Molar conductance (cm2 Cl-'/mole) at temperature:

Concentration Molecular Degree of Concentration (mole) weight association of adduct 25 "C 35 "C 45 "C

'Compound in nitrobenzene solution.

respectively. We found shifts of 126, 138, and The assignments of other i.r. bands are given in 116 cm-' for the v(NH) of the 2-pyrrolidinone Table 111. complexes of CoCl,, CoBr,, and CoI,. In order Acknowledgment to obtain a of 2-~~rro1idinone, where The authors gratefully acknowledge financial the site of coordination is expected to be oxygen support from the National Research Council of (1 I), we prepared the complex to the ligand with Canada. BC1,. It was found to be a 1:l com~ound and sho\;led a lowering of v(C0) of 45 cm-' and a I. S. K. MADAN and J. A. STURR. J. Inorg. NUC~.

lowering of v(NH) of 89 cm-'. Chern. 29, 1669 (1967). 2. P. P. SINGH and R. RIVEST. Can. J. Chem. 46, The earlier conclusion, that coordination 2361 (1968).

through nitrogen of cyclic thioamides is accom- 3. German Patent No. 1 033 207 (1958); Chem. Abstr. 54, 174178 (1960). panied by a lowering the v(NH) of about 4. F. A. COTTON, D. M. L. GOODGAME, and A. S ~ c c o .

200 cm-' does not, therefore, conflict with the J. A,. them. so,. 83, 4157 (1961). present findings of a lowering of the v(NH) of 5. V. GUTMANN and 0. BOHUNOVSKY. Monatsh. Chem.

99, 740 (1968). about loo cm-' in the case of coordination 6. A. FINE. J. Am. Chem. Soc. 84, 1139 (1962). through oxygen. 7. F. A. COTTON, D. M. L. GOODGAME, and M. GOOD-

As the i.r. spectra in Nujol, unlike those in GAME. J. Am. Chem. Soc. 83,4690 (1961).

solution, indicate that all ligand molecules are 8. J. E. KATON, W. R. FEAIRHELLER, and J. V. PUSTINGER, JR. Anal. Chern. 36, 2126 (1964).

coordinated, and from the conclusion drawn 9. K. KUROSAKI. Nippon Kagaku Zasshi, 82, 1691 (1961); Chem. Abstr. 58, 13312d (1962). from the electronic spectra, it seems reasonable K. MIzuTANI and K. STONE. z. Anorgo Allgem.

to assume a structure [CoL,X]X for the com- Chem. 350, 216 (1967). plexes in the solid phase. 11. W. GERRARD, M. F. LAPPERT, H. PYSZORA, and J. W.

WALLIS. J. Chem. Soc. 2144 (1960).

Ferric benzoylacetanilides

A. SYAMAL Department of Chemistry, Emory University, Atlanta, Georgia, U.S.A.

Received September 10, 1968

Ferric chelates with benzoylacetanilide and benzoyl-metanitroacetanilide have been prepared and characterized. The complexes are dark red in color and are paramagnetic (ptII = 5.8 B.M.). Electrolytic conductance, electronic spectra, and infrared spectra of the complexes are reported. Absorption spectra point to weak donor ability of the ligands in comparison to acetylacetone. The complexes are octahedral.

Canadian Journal of Chemistry, 47, 1693 (1969)

There has been appreciable interest in the ferric lished, nothing has appearedso far intheliterature p-diketone complexes from the standpoint of concerning the ferric complexes of benzoylaceta- syntheses, spectra, and structure (1-5). Though nilides, which are capable of keto-en01 tautomer- ferric complexes with P-diketones are well estab- ism shown by P-diketones. Little work has been

Can

. J. C

hem

. Dow

nloa

ded

from

ww

w.n

rcre

sear

chpr

ess.

com

by

Uni

vers

ity o

f A

uckl

and

on 1

1/09

/14

For

pers

onal

use

onl

y.

1694 CANADIAN JOURNAL O F CHEMISTRY. VOL. 47, 1969

TABLE I Analyses, molar conductance, and magnetic moment of iron(II1) chelates

Magnetic Analyses moment

Molar conductance (B.M.) Comulexf XFe X N O/,HzO* W1 cmZ mole-I T = 298 "K

[ F ~ ( C I S H I ~ ~ Z P \ T ) ~ I Found: 7.48 5.56 1 . 5 5.84 Calcd : 7.27 5.45

[Fe(C1 &I1 I O ~ N Z ) ~ I . ~ H Z O Found: 6.16 9.08 3.52 1 . 8 5.85 Calcd : 5.95 8.92 3.82

*The water molecules stay outside the coordination zone as is evident from their ready loss at 11O0C with no color change accompanying dehydration.

tWhere C15H1302N = benzoylacetanilide, C6HS-C-CH2-GNHCLH5, C15H1204N2 = benzoyl-metanitroacetanilide. I1 I1

reported concerning the complexing ability of The analyses, molar conductance, and magnetic benzoylacetanilides. syntheses of oxo-vana- moment of the compounds are recorded in Table I. The

electronic spectral characteristics of the complexes are dium(IV), dioxo-molybdenum(VI), dioxo-urani- presented in Table II. um(VI), Ti(IV),Cu(II) (6, 7), and reports con- cerning the estimation of titanium, vanadium, Results and Discussion and mercury (8) are all that have appeared so far. hi^ report describes the syntheses and character- When alcoholic solution of benzoylacetanilides

ization of ferric chelates with benzoylacetanilide is added to an of Fe3'9 a fine

and benzoylmetanitroacetanilide. purple color is formed. Formation of this purple color is characteristic of benzoylacetanilides and

Experimental Ferric sulfate hexahydrate was a product of E. Merck

(Germany). Benzoylacetanilide and benzoyl-metanitro- acetanilide were prepared according to the published procedures (6, 9).

General Method of Syntheses of the Cotnplexes Ferric sulfate hexahydrate (1.0 g, 2 mmoles) was dis-

solved in 30 ml of hot water and a few drops of concen- trated HzS04. The appropriate amount of the ligand used was weighed out for a 1:3, Fe3+:ligand con~plex. This was dissolved in a minimum amount of hot ethanol and this solution was added to the Fe3+ solution. T o the resulting violet solution, dilute sodium acetate was added dropwise with stirring. The separated dark red oily layer was taken up with ethanol. Water was added dropwise to the ethanol solution resulting in the formation of dark red crystals. These crystals were suction filtered and washed with hot water followed by a warm 50% water- ethanol solution. The product was dried in a desiccator over CaCI, and P4010.

Methods The electrolytic conductance was measured with the

help of a conductivity bridge (fitted with magic eye) and a dip type cell. Room temperature magnetic susceptibility measurements were taken in a Gouy Balance using A.R. CuS04.5HZ0 as the calibrant. Electronic absorption spectra in the region of 12.5-50 kK were recorded in methanol solution (concentration varying from 0.5 x

to 1.0 x M ) with the help of a Perkin-Elmer spectrophotometer. Infrared (i.r.) spectra were measured in Nujol mulls on a Perkin-Elmer recording spectropho- tometer, model 21.

no other metals interfere in this color reaction. The analytical data show that the Fe3' : ligand ratio in thecomplexes is 1 :3. The complexes are in general insolublein water and solublein methanol, ethanol, chloroform, and carbontetrachloride. The electrical conductance measurements of the complexes in methanol (A, -- 1 a-I at 25 "C) indicate nonelectrolytic nature of the complexes. The complexes are all paramagnetic and record a magnetic moment (perf - 5.8 B.M.) close to the spin-only value. This value is in close agreement with the high-spin octahedral structure with 5 unpaired electrons in 3d5 system and having Fe3' in the 6S ground state level (10). The U.V.

and visible spectra of the complexes exhibit 2 intense bands around 20.6 and 27.5 kK. These two bands are electron transfer bands corresponding to the transitions n -> v5 and v, + n*, respectively (4). The high molar absorp- tivity of these bands is indicative of electron transfer bands rather than the weak, spin-forbid- den bands (3, 4). The latter are the only type of d o d transitions expected in an 0, symmetry ~ e , + environment. Probably the characteristic spin-forbidden bands are obscured by the low energy tails of the electron transfer bands and this observation is in line with other octahedral spin- free iron(II1) complexes (10). The corresponding

Can

. J. C

hem

. Dow

nloa

ded

from

ww

w.n

rcre

sear

chpr

ess.

com

by

Uni

vers

ity o

f A

uckl

and

on 1

1/09

/14

For

pers

onal

use

onl

y.

NOTES

TABLE I1

Numerical values for the electron transfer transitions of Fe(II1) complexes obtained by the choice of parameters?

I. n -> v5 11. n + v3 111. v5 + n* IV. v3 + n*

Ligand Calcd. Found Calcd. Found Calcd. Found Calcd. Found

Benzoylacetanilide 22 20.6(3.22) 40 - 46 - 28 27.5(3.69) Benzoyl-metanitro-

acetanilide 22 20.6(3.20) 40 - 46 - 28 27.2(3.50) Acetylacetone$ 23 23.2(3.47) 41 - 45 - 27 28.5(3.55)

tV - 30 kK V , = 18 kK, A = 18 kK, D = 4.5 kK, E - A = 4 kK (1 kK = IOOOcm-'). ~ ~ A k e n from'ref. 4 for comparison. Figures in the parentheses indicate loge.

electron transfer bands in tris(acety1acetonato) iron(II1) occur at 23.2 kK (log E = 3.47) and 28.5 kK (log E = 3.55) (3). The band positions sug- gest that the ligand field of tris(acety1acetonato) iron(II1) is stronger than those of tris(ben- zoylacetanilido) iron(II1) and tris(benzoy1-met- anitroacetanilido) iron(II1). In the uranyl com- plexes (6) of the present ligands, the OUO stretch frequency was also observed at lower energy than those of the OUO stretch frequency of bis(acety1- acetonato) U02(VI). Thus the electronic absorp- tion spectra undoubtedly identify the ligands benzoylacetanilides as weak donors in compari- son to acetylacetone.

Generally 4 electron transfer transitions from or to the n levels of the ligand are expected for octahedral high-spin complexes of the type Fe(acac), or Fe(benzoylacetanilide),. These 4 different electron transfer spectra are (4) I, n -> v5 ; 11, n -> v, ; 111, v5 -> n* ; and IV, v, -> n*. For a high spin d5 configuration the dependence on the parameters V,, V2, E - A, and D of the transi- tions I, 11,111, and IV is given as V, - 5(E - A) + 813 D, V1 + A - 5(E - A) + 813 D, V2 + 4(E - A) + 813 D, and V2 - A + 4(E - A) + 813 D, respectively, where Vl and V2 are related by the equation: V2 + V, - (E - A) = 44 kK (4). D is roughly 7B for d electrons, and is known from internal transitions in the d shell of similar complexes to be approximately 4.5 kK. From the experimental results the value of T", is derived, noting that the strong band of Fe(benzoy1acetani- lide), or Fe(benzoy1-metanitroacetanilide), at 20.6 kK must belong to the category I. A, the ligand field splitting parameter, is assumed to be of the same value (18 kK) as in Fe(acac), due to the very close positions of these two types of ligands in the spectrochemical series, and it allows the calculation to be made without prior

knowledge of the spectrum. Thus good agreement between the calculated and observed energies of the electron transfer transitions was obtained by choice of suitable parameters (cf. Table 11). The electron transfer bands I1 and I11 were not ob- served in these complexes as these bands were obscured by the intense charge-transfer spectra at the calculated frequencies. In the correspon- ding acetylacetonato complex also, these bands were not observed due to the same reason.

The i.r. spectra of the complexes were charac- terized by the presence -of chelated carbonyl absorptions. In both the complexes the normal carbonyl vibration of the ligand is replaced by metal coordinated carbonyl absorptions at much lower frequencies. The carbonyl spectrum of the chelating ligands benzoylacetanilide and benzoyl- metanitroacetanilide occur at 1700 and 1670 cm-', respectively. Tris(benzoylacetani1ido) iron(II1) and tris(benzoy1-metanitroacetanilido) iron(1II) exhibit chelated carbonyl absorptions at 1.66 and 1.625 kK, respectively. The frequency of the carbonyl band of the ligands is therefore shifted to lower frequency (- 0.04 kK) by coordination with ferric ion.

Acknowledgment

Thanks are due to Dr. R. L. Dutta of Depart- ment of Chemistry, Ohio State University, Columbus, Ohio, U.S.A., for his interest in the work.

1. A. COMBES. Compt. Rend. 105, 868 (1887). G. T. MORGAN, H. D. K. DREW, and C. R. PORTER. Ber. 58, 333 (1925).

2. B. C. GUHA. Proc. Roy. Soc. London, Ser. A, 206, 353 (1931). R. H. HOLM and F. A. COTTON. J. Am. hem. SOC. 80, 5658 (1958). T. S. PIPER and R. L. CARLIN. Inorg. Chem. 2, 260 (1963). D. T. FARREN and M. M. JONES. J. Phys. Chem. 68, 1717 (1964).

Can

. J. C

hem

. Dow

nloa

ded

from

ww

w.n

rcre

sear

chpr

ess.

com

by

Uni

vers

ity o

f A

uckl

and

on 1

1/09

/14

For

pers

onal

use

onl

y.

1696 CANADlAN JOURNAL OF CHEMISTRY. VOL. 47, 1969

3. D. W. BARNUM. J. Inorg. Nucl. Chem. 21, 221 7. A. SYAMAL. J. Indian Chem. Soc. 44, 656 (1967); (1961); 22, 183 (1961). 45, 755 (1968).

4. C. K. JORGENSEN. Acta Chem. Scand. 16, 2406 8. A. K. SARKAR and J. DAS. Anal. Chem. 39, 1608 (1962). (1967); Anal. Letters 1, 325 (1968).

5. R. B. ROOF, JR. Acta Cryst. 9, 781 (1956). B. 9. H. GILMAN and A. H. BLATT. Org. Syn. 39, 2 MOROSIN and J. R. BRATHOVDE. Acta Cryst. 17,705 (1954); 39, 32 (1954). (1964). 10. F. A. COTTON and G. WILKINSON. Advanced inor-

6. A. SYAMAL. J. Inorg. Nucl. Chem. Letters, 4, 543 ganic chemistry. Interscience Publishers, Inc., New (1968). York. 1966. p. 861.

Reaction of atomic hydrogen with tetrafluoroethenel

LEI TENG AND W. E. JONES Department of Chemistry, Dalhousie University, Halifax, Nova Scotia

Received August 20, 1968

Hydrogen atoms, generated in a Wood's electric discharge tube, were allowed to react with tetra- fluoroethene. The products of the reaction were found to be HF, C2F?H, C2H2, C2F2H2? C2F4H,, C2FH3, C2H4, and CHF,. The formation of the products with the exception of H F was studied quanti- tatively from 30-330 "C.

Canadian Journal of Chemistry, 47, 1696 (1969)

Introduction

The reactions of atomic hydrogen with fluoro- carbons have received only summary attention in the past. Chadwell and Titani (I), using the discharge tube method at room temperature, found no reaction of hydrogen atoms with methyl fluoride. Later, Dacey and Hodgins (2) investi- gated the mercury photosensitized reactions of the mixture of tetrafluoromethane and hydrogen molecules but again no evidence was found for the occurrence of a reaction. Clark and Tedder (3-5) studied a series of free radical substitutions in aliphatic compounds. They found that the first step in the reactions of hydrogen atoms with bromotrichloromethane and fluorotrichloro- methane was the abstraction of a halogen atom. The resulting trihalomethyl radical added H to form a vibrationally excited molecule, which either stabilized or decomposed by elimination of HX. If fluorocarbons were the reactant species, the elimination of H F always occurred in pref- erence to stabilization.

in an attempt to get an insight into the reaction mechanism.

Experimental Hydrogen was supplied by Canadian Liquid Air Ltd.

Ethane, ethene, hexafluoroethane, acetylene, and 1,l- difluoroethene were obtained from Matheson Company of Canada Ltd.; trifluoromethane and tetrafluoroethene were obtained from Pierce Chemical Company. Each of these gases was frozen in a liquid nitrogen trap and traces of non-condensable gases were pumped off.

The flow system for this work was a typical Wood- Bonhoffer system similar to those described by many workers. Dry hydrogen flowed into each end of the V-shaped discharge tube. The power from a 3000V Hammond transformer was rectified and supplied to the discharge tube through a 5000R resistor. With 80 V across the primary of the transformer, and a hydrogen pressure of 4.60 mm Hg, a stable discharge and a stable production of atomic hydrogen were obtained. A molecular hydrogen flow rate of 182 x moles/s produced the above pressure when a Cenco HyperVac No. 23 was used as the vacuum pump. The hydrogen atom flow rate was estimated at 0.8 x moles/s by reaction with 2-dimethylethylenimine (7).

The mixture of atomic and molecular hydrogen passed from the discharge tube into a cylindrical reaction vessel

The kinetics of the reaction of hydrogen atoms made from 25 mm 0.d. Pyrex tubing. Tetrafluoroethene

with tetrafluoroethene were investigated by was admitted to the hydrogen stream through a jet centered in the reaction vessel. The wall of the reaction

and Robb (6) . did not study vessel was thoroughly poisoned with phosphoric acid. the products of the reaction and it thus seemed Qualitative and quantitative analysis of the reactant worthwhile to study the products of this reaction and products was made by gas-liquid chromatography

(g.1.c.) on a column of &in. copper tubing packed with silica gel which had been coated with 3% squalane (8).

'Presented at the 51st Conference of the Chemical Identification was made by comparison of retention Institute of Canada, Vancouver, June 1968. times, and where necessary, from mass and infrared (i.r.)

Can

. J. C

hem

. Dow

nloa

ded

from

ww

w.n

rcre

sear

chpr

ess.

com

by

Uni

vers

ity o

f A

uckl

and

on 1

1/09

/14

For

pers

onal

use

onl

y.