Nickel linear chains

Bamboo-shaped tubes. A carbon tube with a peculiar shape looking like bamboo, produced by the arc evaporation of nickel-loaded graphite, is shown in Fig. 8. The tube consists of a linear chain of hollow compartments that are spaced at nearly equal separation from 50 to 100 nm. The outer diameter of the bamboo tubes is about 40 nm, and the length typically several /im. One end of the tube is capped with a needle-shaped nickel particle which is in the normal fee phase, and the other end is empty. Walls of each compartment are made up by about 20 graphitic layers[34]. The shape of each compartment is quite similar to the needle-shape of the Ni particle at the tip, suggesting that the Ni particle was once at the cavities. 

Halide bridged nickel(II)/platinum(IV) and palladium(II)/platinum(IV) complexes with onedimensional linear-chain structures have been studied extensively.556-559 These are analogous to the linear-chain platinum(II)/platinum(IV) systems described in Section 6.5.13 and have similar broad and intense intervalence bands.556-559 However, they have weaker metal-metal interactions resulting in more localized valences than the all platinum analogues.556-559... 

The physical properties of low dimensional magnetic materials have attracted the attention of many researchers.3015 Several nickel(II) linear chain complexes have been synthesized and... 

Both the linkages to form planes and their stacking are different depending on the kinds of A and M metals. The trigonal planar [MN3]6- unit was also observed in Ca6FeN5.18 The existence of double metal nitrides has not yet been reported for cobalt. Cobalt is between iron and nickel in the periodic table. It is an open question whether the double metal nitride with cobalt has a linear chain or a trigonal planar coordination. 

Two nitrogen atoms are linearly coordinated to nickel atoms in all ANiN. They form o-bonds using the 2pz orbitals of nitrogen through a hybridization of the 3(1 and 4s orbitals of nickel. The valency of nickel is formally Ni+ with 3d9. The unpaired electron is accommodated in an antibonding a or it orbital to make the compound metallic. The jt bond character in the linear chain has been pointed out in YCoC which is isostructural to CaNiN.19 The calcium d-character also contributes to the lowest free-electron-like band at the T point.20... 

Recent synthetic and spectroscopic work has concentrated on the study of structurally related linear-chain palladium complexes (7, 8), on the possibility of synthesising related nickel complexes, and on the study of mixed-metal mixed-valence complexes of the sort... 

ONE-DIMENSIONAL LINEAR-CHAIN COMPLEXES OF PLATINUM, PALLADIUM AND NICKEL... 

Tridentate ligands of the linear type having donor sets P3, AS3 or P As3. t, where the donor atoms are connected by o-phenylene, ethylene or trimethylene chains, were found to form stable complexes with nickel(II) salts.1350 Listings of the most common ligands and nickel(II) complexes are given in Tables 67 and 68, respectively. 

A particularly valuable use lor chlorparaffins is in preparation of linear, primarily internal olefins as fcedslock Ihr long-chain synthetic oxoalcohols. Typically. ii-paraffins (C M -Cu 1 are chlorinated in a IIiodized bed at ahoul 300 C. Conversion is maintained low to limit multiple chlorination. Aher separation of the monoclilorinaicd alkanes hy distillation, dehydrochlo-rinalion over nickel acetate at 3(K)LC yields the desired internal olefins. Unreacied paraffins are recycled. 

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