NiP structure

The structure of MnP is a distorted variant of the NiAs type the metal atoms also have close contacts with each other in zigzag lines parallel to the a-b plane, which amounts to a total of four close metal atoms (Fig. 17.5). Simultaneously, the P atoms have moved up to a zigzag line this can be interpreted as a (P-) chain in the same manner as in Zintl phases. In NiP the distortion is different, allowing for the presence of P2 pairs (P ). These distortions are to be taken as Peierls distortions. Calculations of the electronic band structures can be summarized in short 9-10 valence electrons per metal atom favor the NiAs structure, 11-14 the MnP structure, and more than 14 the NiP structure (phosphorus contributes 5 valence electrons per metal atom) this is valid for phosphides. Arsenides and especially antimonides prefer the NiAs structure also for the larger electron counts. 

Another distorted variant of the NiAs structure occurs in NiP which is stable only above 850° C (159). In the orthorhombic NiP structure the distortions are stronger than in the MnP type (Fig. 44) but like in MnP the metal atoms form zig-zag chains with Ni—Ni = 2.53 A. The coordination of the nickel atoms is modified insofar as they are shifted towards a comer of the distorted anion octahedra. As a result there are only five phosphorus atoms in contact with the central nickel atom. The anions themselves are arranged in pairs with a P—P distance of 2.43 A, which roughly corresponds to the length of a half bond. In the absence of cation-cation bonds the P—P pairs would lead to divalent Ni and non-metallic properties would be possible. In the actual structure the Ni—Ni bonds exclude semiconductivity which, moreover, cannot be expected in a high-temperature phase. 

Fig. 2.30 Comparison of antiparallel hairpin structures in / -peptides 120-122. (A) / -Pep-tides 120, 121 with a 12-membered R/S dini-pecotic (Nip or/ -HPro) turn segment (gray color). Summary of backbone-backbone and side-chain-side-chain NOEs collected in CD2CI2 and X-ray crystal structure of 121 (stereo-view) [154, 193], The intramolecular H-bond N" 0 distances are shown. The angles (N-H -O) are 170.8° (inner H-bond) and 1 72.3 ° (outer H-bond). (B) jS-Peptide 122 with...

The NiAs structure and distorted variants. The images for MnP and NiP show the same section as the image for NiAs in the upper left. 

Amorphous NiP alloys with > 10% P (generally obtained by deposition from acidic electrolytes) are non-magnetic (see [66] and references therein), as required of the underlayer for thin-film media. Although the structure of these alloys is generally assumed to be a solid solution of P in Ni, a recent report [67] has suggested that NiP with 7.4-10% P deposited from acid sulfate electrolytes is better represented by a microcrystalline structure composed of 4-5 nm fee NiP solid-solution grains. 

The influence of the underlayer was demonstrated by Mirzamaani et al. [74] and by DiMilia et al. [75]. Electroless CoP was deposited from a solution yielding an intrinsically isotropic structure onto NiP that had undergone various pretreatments. When the NiP was exposed to a NaOH treatment before CoP deposition, good inplane magnetic properties resulted, but deposition on a chemically or electrochemically pre-reduced NiP surface gave unacceptable magnetics. These authors found... 

Our focus is on the most comprehensively studied series, the monophosphides of the first-row transition metals, whose structures successively distort from NaCl-type (ScP) to TiAs-type (TiP), NiAs-type (VP), MnP-type (CrP, MnP, FeP, CoP), and NiP-type, forming stronger metal-metal and phosphorus-phosphorus bonding with greater electron count (Fig. 11) [63-65], The P atoms are six-coordinate, but... 

Tegelaar E, deLeeuw J, Largeau C, Derenne S, Schulten H, Muller R, Boon J, Nip M, Sprenkels J (1989) Scope and limitations of several pyrolysis methods in the structural elucidation of a macromolecular plant constituent in the leaf cuticle of Agave americana L. J Anal Appl Pyrolysis 15 29-54... 

Diazepam and its nordiazepam, oxazepam, and temazepam metabolites are well retained by the MIP, while they are much less retained on NIP, also exhibiting large RSD. Other benzodiazepines of similar structures (Figure 1.50) were well retained on the MIP, showing that this template can be used for the general class of benzodiazepines. Two benzodiazepines studied, chlordiazepoxide and flunitrazepam, were poorly retained, indicating poor fit of these structures into the templated MIP. 

NiAs distortion structures. The characteristics of a number of structures have been described by Pearson (1972) in terms of distortions of the NiAs type. Different variants have been considered, of which the following new prototypes having a 1 1 stoichiometry are typical examples mS8-CrS, oP8-MnP, oP16-NiP, hP24-aFeS. The oP8-MnP type is described here below. 

Consider the procedure for immobilizing an enzyme using polyurethane technology. A solution of the enzyme is produced in water. The solution is then emulsified with a hydrophilic polyurethane prepolymer. The emulsion is applied to the structural members of a reticulated foam by means of nip rollers. After curing... 

Fig. 1. Structure of the antibody fusion protein. The Fab-like form is formed from a X light chain derived from the J558L cell line, and the chimenc heavy chain produced from the vector. The heavy chain consists of a variable region with NIP binding activity, CH1, hinge and part of the CH2 domain of murine y2b heavy chain, and the foreign gene. The fusion protein may be secreted in this form or as an F(ab )2-like form consisting of 2 Fab-like molecules linked at the hinge region by three disulfide bonds...

CALCIUM. CAS 7440-70-21. Chemical clement, symbol Ca. at. no. 20, at. in. 40.1)8. periodic table group 2 talkaline earths), nip X37-X4IU, bp 1.484 C, density 1.54 g/ent Isingle crystal). Elemental calcium has a luce-centered cubic crystal structure when at room tempcruturc. transforming to a body-centered cubic structure at 44X C... 

EUROPIUM. [CAS 7440-53-11. Chemical clement symbol Hit. at no 63. al. wt. 151.96, sixth in the Lanthanide Series in the periodic table, nip 822 C. bp 1529 C. density 5.245 g/cm1 20 C). Elemental europium has u body-centered cubic crystal structure at 25"C. The pure metallic europium... 

MERCURY. [CAS 7439-97-6, Chemical element, symbol Hg. at. no. 8(1. at. vvt. 21X1.59. periodic table gmup 12. nip —3X.84 C. bp 356.5x C. density 13.546 g/cin (liquid). 14.193 g/cm isolid). Solid mercury has a rhomhohedral crystal structure The element, sometimes referred to as quicksilver, is a silver-while liquid metal at standard conditions. There are seven stable isotopes of mercury. " Hg " Hg through "- Hg. and JHe. and seven radioactive isotope s., Hg through "Tig. l,7Hg. " Hg. and " Hg. With exception of l>JHg (half-life of approximately 130 days) and 1415Hg thalMtl e of approximately 46 daysl. the half-lives of the radioactive isotopes are short, measured in terms ol minutes or hours. 

Attempts to correlate structure and spectra in the case of di- and polysubstituted compounds have again been largely unsuccessful. The spectra of various dialkylbenzo[6]thiophenes are very similar to those of monoalkyl derivatives, except that the bathochromic shift relative to benzo[6]thiophene is more pronounced.104 134-187 It is claimed that the sharp peaks in the 290-305 nip. region of the spectra of 5-substituted 2,3-dialkylbenzo[6]thiophenes are replaced by points of inflection in similar 6-substituted compounds, allowing such isomers to be distinguished.81104 136 Several 2-acetyl- and 3-acetyl-... 

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