July 5, 1963
2021
COMMUNICATIONS TO THE EDITOR
associated hydrogen^,'^^^^ there is, in the absence of an appreciable isotope effect, equal probability of loss of any of the top five borons as borane groups. After removal of one normal borane the labeled boron could be found in a 6(9) or 5(7,8,10) position in the resulting B10H13- fragment, and, after a second exchange, the label, if it remained in the molecule, could be found in any position. As yet there is no evidence for the existence of an isolable BllHla- salt but the model is useful in rationalizing this most unusual exchange reaction. Irrespective of the precise mechanism of exchange, the fact that boron randomization occurs implies that interpretation of the results of isotopic tracer studies will have t o be made with caution in this and related boron hydride systems. Acknowledgments.-This work was supported by National Science Foundation Grant G-14595. We acknowledge the useful discussions of this work with Donald F. Gaines.
non-condensable gas formed gave 32.5 cc. (1.45 mmoles) of carbon monoxide and 3.25 cc. (0.145 mmole) of hydrogen. On the basis of a composition HzGe[Mn(CO)5]2 the volumes of carbon monoxide and hydrogen expected were 34.0 and 3.4 cc., respectively. The proton n.m.r. spectrum (60 Mc.) of bis-(pentacarbonylmanganese) -germane in chloroform shows a single absorption a t 6.67 r . Proton resonances in germanes have been observed a t 6.6-6.9 T . ~Under high resolution, the infrared spectrum of the new germanium-manganese compound (cyclohexane solution) shows a Ge-H stretching band a t 2083 (s) cm.-', and carbonyl bands a t 2016 (vs), 2008 (s) and 1992 (s) an.-'. Additional bands occur a t 654 (s), 645 (s) and 633 (m) crn.-'. Bis-(pentacarbony1manganese)-germane has been stored for months in air without apparent decomposition. I t is also formed, but in small amount, by heating dimanganese decacarbonyl with germane a t 140', but the desired product is difficult t o recover (12) From M.O. arguments it is not desirable t o propose full 5-fold symfrom unreacted manganese carbonyl, and the gas metry for both boron and hydrogen positions in a diamagnetic model of this form, a s pointed out by W. N. Lipscomb (private communication). T h u s non-condensable a t - 196' contains appreciable quana static form of t h e BuHls- model may be constructed with t h e 5 hydrogens tities of carbon monoxide. No manganese pentain excess of 1 per boron distributed among both bridging and -BHa positions carbonyl-substituted germanes were recovered from around t h e open t o p of t h e molecule. reactions between germane or potassium germy1 and (13) Hydrogen tautomerism in boron hydrides has been discussed by R. E. Williams, J . Inorg. Nucl. Chem., 20, 198 (1061). manganese pentacarbonyl chloride or bromide. Apparently the reaction between germane and manCONTRIBUTION No. 1113 RILEYSCHAEFFER DEPARTMENT OF CHEMISTRY FREDTEBBE ganese pentacarbonyl hydride does not proceed via a INDIANA UNIVERSITY simple substitution mechanism BLOOMINGTON, INDIANA GeH4 nHMn( C0)s + GeH4-.[ Mn( CO),] ,, nHz RECEIVED MAY16, 1963 since we have been unable t o detect even a trace of H3GeMn(C0)5 or HGe [Mn(CO)5]3among the products. Chemistry of the Metal Carbonyls. XXIV. Perhaps the first stage of the reaction is reduction, by the manganese pentacarbonyl hydride, of germane t o Bis-(pentacarbony1manganese)-germanelr2 GeH2, followed by addition of two manganese pentaSir : carbonyl groups. Some support for this idea comes We wish t o report air-stable bis-(pentacarbonylmanfrom preliminary observations on the effect of manganese) -germane. This unusual compound was obganese pentacarbonyl hydride on silane. Reaction is tained by a new type of reaction involving treatment of slow and appears t o follow a different course from that a transition metal hydride with a volatile hydride of a involving germane, forming very air-sensitive colored main group element. solids and manganese carbonyl. It is well known t h a t In a typical preparation 630 mg. (3.23 mmoles) of the Si(I1) state is not as easily attained as the Ge(I1) manganese pentacarbonyl hydride3 and 102.5 cc. state. (4.57 mmoles) of germane4 were sealed under vacuum Acknowledgment.-We wish to thank the Gerwith 390 mg. (3.19 mmoles) of tetrahydrofuran in a manium Research Committee for a gift of germanium 100-cc. Pyrex bulb. After 8 days a t room temperature dioxide. (15") the reaction vessel was opened t o the vacuum system and hydrogen (64.8 cc., 2.89 mmoles) containing (6) J. E. Drake and W.L. Jolly, J . Chem. Soc., 2807 (1962). a trace of carbon monoxide was removed with a Toepler DEPARTMENT OF CHEMISTRY A. G. MASSEY pump. Fractionation of the condensable gases showed A . J. PARK QUEENMARYCOLLEGE F. G. A. STONE that 1.61 mmoles of germane and 2.72 mmoles of manUNIVERSITY OF LONDON E. l., ENGLAND LONDON, ganese pentacarbonyl hydride had reacted. SublimaRECEIVED MAY13, 1963 mm.) of the crystals remaining in the tion (80' a t reaction vessel afforded 600 mg. (95% yield based on Mn(C0)gH consumed) of very pale yellow HzGe[MnElectron-Donor Properties of Zinc Phthalocyanine (C0)5Ir (m.p. 87-88'), moderately soluble in organic Sir : solvents. Analytical samples from this and other I t has been shown that electron transfer from preparations were obtained by additional sublimations. phthalocyanine, in the ground and excited states, to .4nd Calcd. for CloHzOloGeMnz: C, 25.8; H, 0.4; chloranil is an efficient mechanism of charge carrier Mn, 23.6; mol. wt., 465. Found: C, 25.5, 25.5, production in semiconducting films. Such processes 26.6; H , 0.3, 0.2, 0.4; Mn, 23.1; mol. ~ t . , ~ 4 7 4 . also have considerable biological importance. Recent A sample (70.6 mg., 0.152 mmole) of bis-(pentastudies of the luminescence and associated properties of carbony1manganese)-germane was heated a t 180' (8 phthalocyanines in this Laboratory appear to demonhr.) with iodine (2 g.). Combustion analysis of the strate analogous electron-donor tendencies in fluid (1) P a r t XXIII: P . M. Treichel, M. A. Chaudhari a n d F. G. A . Stone, solution. J . Ovgonometallic Chem., in press; p a r t XXII: D. W. McBride, S. L. StafI t was found that the absorption band of zinc phthaloford and F.G. A. Stone, J. Chem. Soc., 723 (1963). cyanine a t 668 mp is depressed and broadened in the (2) T h e research reported herein has been sponsqred by t h e U. S.Department of t h e Army, through its European Research Office. presence of the strong acceptors (ie., Lewis acids)
+
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(3) (a) W. Hieber and G. Wagner, Z . Nalurforsch., 13b,338 (1958); (b) I
