No abstract

No abstract

The wave nature of matter is a key ingredient of quantum physics and yet it defies our classical intuition. First proposed by Louis de Broglie a century ago, it has since been confirmed with a variety of particles from electrons up to molecules. Here we demonstrate new high-contrast quantum experiments with large and massive tailor-made organic molecules in a near-field interferometer. Our experiments prove the quantum wave nature and delocalization of compounds composed of up to 430 atoms, with a maximal size of up to 60 Å, masses up to m=6,910 AMU and de Broglie wavelengths down to λdB=h/mv≃1 pm. We show that even complex systems, with more than 1,000 internal degrees of freedom, can be prepared in quantum states that are sufficiently well isolated from their environment to avoid decoherence and to show almost perfect coherence.

Little is known about the chemical nature of the recently isolated carbon clusters (C,,, C,,, C,,, and so forth). One potential application of these materials is as highly dispersed supports for metal catalysts, and therefore the question of how metal atoms bind to C,, is of interest. Reaction of C,, with organometallic ruthenium and platinum reagents has shown that metals can be attached directly to the carbon framework. The native geometry of C,, is almost ideally constructed for dihaptobonding to a transition metal, and an x-ray diffraction analysis of the platinum complex [(C6H5)3P]2Pt(q2-C60)-C4H80 revealed a structure similar to that known for [(C,H,)3P]2Pt(q2-ethylene).The reactivity of C,, is not like that of relatively electron-rich planar aromatic molecules such as benzene. The carbon-carbon double bonds of C,, react like those of very electron-deficient arenes and alkenes.

No abstract

Paul J. Fagan received his B.S. In chemistry from Rutgers University in 1976. He obtained a Ph.D. in inorganic chemistry from Northwestern University In 1980. He went on to do postdoctoral work at the University of Wisconsin, Madison. Since 1982, he has been in the Central Research and Development Department of E. I. du Pont de Nemours & Co. His professional interests are in the general fields of inorganic and organometallic chemistry, Including homogeneous catalysis, rational synthesis of molecular solids, and polysilane chemistry. Joseph C. Calabrese graduated with a B.S. from Allegheny College in 1964 and received a Ph.D. from the University of Wisconsin, Madison, in 1971. He is currently a Staff Scientist at Du Pont and has used crystallography for over 25 years to study a variety of organic, organometallic, and inorganic chemistry problems. Brian Malone was born In London, England, and attended London University (B.Sc. 1958 , Ph.D. 1963). After a postdoctoral fellowship at the California Institute of Technology, he joined Du Pont in 1966, where he has worked mainly on heterogeneous catalysis and plasma chemistry.

A single-crystal X-ray structural analysis of the complex [Cp*R~(p~-Cl)1~ (1, Cp* = q5-C5(CH3),) has been performed (triclinic, P1 (No. 2); a = 11.281 (5); b = 11.354 (4); c = 18.846 (5) A; a = 82.20 (2)O, j3 = 82.03 (3)O, y = 65.45 (4)O; V = 2166.3 A3, 2 = 2). The complex contains a distorted cubic array of ruthenium and chlorine atoms. The complex 1 is a useful precursor to Ru(O), Ru(II), and Ru(1V) pentamethylcyclopentadienyl complexes. Reaction of 1 with donor ligands yields Cp*RuL2Cl complexes (L = CO, P(CHd3). With dienes, 1 yields the complexes Cp*Ru(q4-diene)C1 () which in turn can be reduced with lithium to yield the corresponding anionic diene complexes Cp*Ru(q4-diene)-Li+.DME (DME = 1,2-dimethoxyethane). The complex [Cp*Ru(p3-I)], has also been prepared and reacts with l,&butadiene to yield Cp*Ru(q4-scis-1,3-butadiene)I, which has been structurally characterized by a single-crystal X-ray analysis (monoclinic b, P2,/c (No. 14); a = 7.177 (2); b = 14.362 (3); c = 13.788 (2) A; 0 = 93.39 (1)O; V = 1418.7 A3, 2 = 4).Reaction of 1 with ethylene yields the complex [Cp*Ru(4-C2H4)Cl],, which can be converted to the complex C~* R U (~~-C~H , )~L~.With allyl chloride, 1 yields the oxidative addition product Cp*Ru(03-C3H5)Cl,.

Perfluoroalkylated nanospheres have been prepared by reaction of fullerenes with a variety of fluoroalkyl radicals. The latter are generated by thermal or photochemical decomposition of fluoroalkyl iodides or fluorodiacyl peroxides. Up to 16 radicals add to C(60) to afford easily isolable fluoroalkylated derivatives. The monosubstituted radical adducts were detected by electron spin resonance in the early stages of the fluoroalkylation reactions. These spheroidal molecules are thermally quite stable, soluble in fluoroorganic solvents, chemically resistant to corrosive aqueous solutions, and more volatile than the parent fullerenes. Films of the sublimed material display properties typical for a perfluoroalkylated material.