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The Intercalation of graphite by titanium tetrachloride
CwfJO~ Vol. 17, p. 371
LETTERS TO THE EDITOR The fntercafntfon of graphite by tftanfumtetraeblorfde
(Received13November 19781 It has been reported that graphite is not intercalated by ti~ium tetrachloride[l]. However, both the electronic structure and physical properties of titanium tetrachloride are favourable for intercalation to take place. Further, titanium tctrafluoride is able to inter&ate graphite[2]. The original attempts at intercalation were made in the absence of free cMorine[l]. Subsequently, Rlldorlf[J] showed that the presence of free chlorine was essential for the intercalation of metal chlorides. We report the successful intercalation of graphite by titanium tetrachloride in the presence of free chlorine. Two method8 were used. In one, graphite, together with excess titanium tetrachloride and chlorine were contained in a seafed glass tube at 140°C.In the other, the general method due to Latancette[4] was followed. In this method chlorine was bubbled through a refluxing ~lution of ti~um tetrachloride in carbon tetrachloride in which the graphite was suspended. Both methods yielded intercalated products in which the X-ray d&action patterns showed, inter alii, the absence, or great reduction, of the graphite 002) peak, and the presence of a smafi peak at 9.5 h This 9.5 a. peak was assumed to be due to a first stage intercalation product. However, analysis for Ti content (as TiOz) showed that the most biiy intercalated products had a C:Ti ratio of 32: 1. Inspection of the intercalated products over a period of several days revealed that when they were exposed to laboratory atmosphere titanium tetrachloride was rapidly lost. An indication of this de-intercalation process was the re-appearance of the graphite (002 reflection and, at the same time, the disappearance of the 9.5 d peak from intercalated specimens exposed to atmosphere. We conclude that a first stage ~aphite-ti~ium tetrachloride inter&ate is possible, but that it is unstable under normat atmospheric conditions.
Carbon tetra~~o~de was distill over ~hydrous CaCl~ before use. The sealed tube experiments were conducted as follows. Titanium tetrachloride was introduced into thick-wall Pyrex glass tubes containing dry graphite. The contents were frozen and chlorine distilled in. The quantities were chosen such that there was a 10% excess of TiCl, over the requirement for the production of a first stage intercafate. Similarly, the quantity of chlorine was calculated on the basis of a first stage intercalate with a Ti:CI ratio of 1:4.4. In all cases chlorine was in excess at the completion of the heat@ experiment. The tube and frozen contents was evacuated and sealed under vacuum. Heating experiments were carried out at 140°Cfor periods up to 24 hr. FoBowing the reaction, the exctss volatiie reagents were suborns off, in vacua, at 0°C. The graphite complex was checked for irnp~t~s by optical microscopy and by X-ray diffraction. In the inttrcrdation experiment with CC.4 solvent, chlorine was continuously bubbled through a graphite:Tii&:CCl, mixture in the mole ratio 1: 0.2: 10 at the reflux temperature (80°C).Reflux was continued for periods up to 6hr. The product was filtered and washed with dry CCL. The products were analysed by digestion with concentrated sulphuric acid followed by burning off the graphite at 900°C.The residue was TiOz.
E-AL Purified Kropfmiihl (Bavaria) graphite (flake thickness, 1 x lo-’ m and cross section 5 x 10d4m) was used. The ash content of this graphite was <0.03%. B.D.H. Laboratory Reagent grade titanium tetrachloride and Mathieson bottled chlorine were used.
Victoria University of Wellington
A. G. FREEMAN J. LONERGAN
Chemistry Department Wellington, New ZeafaRd
1. R. C. Croft, Chem. Sot. Quart. Rez. 14, 1 (1960). 2. E. Buscarlet, P. Touzain, M. Armand and L. Bonnetain, Compt. Rend. Hebd. Aead. Sci. C280,1313 (1975). 3. W. Ri_idorS,Advances in Inorganic and Radiochemistry, Vol. 1, u. 233. Academic Press, New York (1959). 4. J.-M. Lalancette, L. Roy and J. Lafdntaide, Can. J. C/rem.54, 2505(1!976).
Carbon Vol. 17, pp. 371-372 PrrgamonPress Ltd.. 1979. Printed in Great Britain
OOCM223/79/0801-0371/$02 00/O
Anwendungder ~plosio~~~~n
auf ~~aate~ynt~e
(Received 2 March
Schon mit einem schwachen mechanischen StoB explodiert heftig und knallend die fliissige Legierung, und zwar Na-K, die mit Kohlenstofftetrachlorid benetzt ist. Diese Legierung bildet sich ohne weiteres bei Zimmertemperatur, wenn metallisches Natrium mit Kalium in Beriihrung kommt. Findet diese Explosion in einem schmalen geschlossenen Raum stat& so gewinnt man in ihm einen hohen Druck und zugieich eine hohe Temperatur. Die hierin sich verwirkiichenden Umstande eignen sich zur Synthese
1979)
von Diamanten gemal der chemischen Gleichung, und zwar CCl,t 4K+4KCl+C.
(1)
Diese Vorstellung fiihrte zur Durchfiihrung des folgenden Versuchs, wobei man zur Diamantensynthese anstatt von CC& und von Na-K KohIenstoffmonofluo~d bzw. Kupfer benutzte. Ein mechanisches Gemenge, das aus Pulver von (CP), und dem von
371
LETTERS TO THE EDITOR The fntercafntfon of graphite by tftanfumtetraeblorfde
(Received13November 19781 It has been reported that graphite is not intercalated by ti~ium tetrachloride[l]. However, both the electronic structure and physical properties of titanium tetrachloride are favourable for intercalation to take place. Further, titanium tctrafluoride is able to inter&ate graphite[2]. The original attempts at intercalation were made in the absence of free cMorine[l]. Subsequently, Rlldorlf[J] showed that the presence of free chlorine was essential for the intercalation of metal chlorides. We report the successful intercalation of graphite by titanium tetrachloride in the presence of free chlorine. Two method8 were used. In one, graphite, together with excess titanium tetrachloride and chlorine were contained in a seafed glass tube at 140°C.In the other, the general method due to Latancette[4] was followed. In this method chlorine was bubbled through a refluxing ~lution of ti~um tetrachloride in carbon tetrachloride in which the graphite was suspended. Both methods yielded intercalated products in which the X-ray d&action patterns showed, inter alii, the absence, or great reduction, of the graphite 002) peak, and the presence of a smafi peak at 9.5 h This 9.5 a. peak was assumed to be due to a first stage intercalation product. However, analysis for Ti content (as TiOz) showed that the most biiy intercalated products had a C:Ti ratio of 32: 1. Inspection of the intercalated products over a period of several days revealed that when they were exposed to laboratory atmosphere titanium tetrachloride was rapidly lost. An indication of this de-intercalation process was the re-appearance of the graphite (002 reflection and, at the same time, the disappearance of the 9.5 d peak from intercalated specimens exposed to atmosphere. We conclude that a first stage ~aphite-ti~ium tetrachloride inter&ate is possible, but that it is unstable under normat atmospheric conditions.
Carbon tetra~~o~de was distill over ~hydrous CaCl~ before use. The sealed tube experiments were conducted as follows. Titanium tetrachloride was introduced into thick-wall Pyrex glass tubes containing dry graphite. The contents were frozen and chlorine distilled in. The quantities were chosen such that there was a 10% excess of TiCl, over the requirement for the production of a first stage intercafate. Similarly, the quantity of chlorine was calculated on the basis of a first stage intercalate with a Ti:CI ratio of 1:4.4. In all cases chlorine was in excess at the completion of the heat@ experiment. The tube and frozen contents was evacuated and sealed under vacuum. Heating experiments were carried out at 140°Cfor periods up to 24 hr. FoBowing the reaction, the exctss volatiie reagents were suborns off, in vacua, at 0°C. The graphite complex was checked for irnp~t~s by optical microscopy and by X-ray diffraction. In the inttrcrdation experiment with CC.4 solvent, chlorine was continuously bubbled through a graphite:Tii&:CCl, mixture in the mole ratio 1: 0.2: 10 at the reflux temperature (80°C).Reflux was continued for periods up to 6hr. The product was filtered and washed with dry CCL. The products were analysed by digestion with concentrated sulphuric acid followed by burning off the graphite at 900°C.The residue was TiOz.
E-AL Purified Kropfmiihl (Bavaria) graphite (flake thickness, 1 x lo-’ m and cross section 5 x 10d4m) was used. The ash content of this graphite was <0.03%. B.D.H. Laboratory Reagent grade titanium tetrachloride and Mathieson bottled chlorine were used.
Victoria University of Wellington
A. G. FREEMAN J. LONERGAN
Chemistry Department Wellington, New ZeafaRd
1. R. C. Croft, Chem. Sot. Quart. Rez. 14, 1 (1960). 2. E. Buscarlet, P. Touzain, M. Armand and L. Bonnetain, Compt. Rend. Hebd. Aead. Sci. C280,1313 (1975). 3. W. Ri_idorS,Advances in Inorganic and Radiochemistry, Vol. 1, u. 233. Academic Press, New York (1959). 4. J.-M. Lalancette, L. Roy and J. Lafdntaide, Can. J. C/rem.54, 2505(1!976).
Carbon Vol. 17, pp. 371-372 PrrgamonPress Ltd.. 1979. Printed in Great Britain
OOCM223/79/0801-0371/$02 00/O
Anwendungder ~plosio~~~~n
auf ~~aate~ynt~e
(Received 2 March
Schon mit einem schwachen mechanischen StoB explodiert heftig und knallend die fliissige Legierung, und zwar Na-K, die mit Kohlenstofftetrachlorid benetzt ist. Diese Legierung bildet sich ohne weiteres bei Zimmertemperatur, wenn metallisches Natrium mit Kalium in Beriihrung kommt. Findet diese Explosion in einem schmalen geschlossenen Raum stat& so gewinnt man in ihm einen hohen Druck und zugieich eine hohe Temperatur. Die hierin sich verwirkiichenden Umstande eignen sich zur Synthese
1979)
von Diamanten gemal der chemischen Gleichung, und zwar CCl,t 4K+4KCl+C.
(1)
Diese Vorstellung fiihrte zur Durchfiihrung des folgenden Versuchs, wobei man zur Diamantensynthese anstatt von CC& und von Na-K KohIenstoffmonofluo~d bzw. Kupfer benutzte. Ein mechanisches Gemenge, das aus Pulver von (CP), und dem von
371