PREPARATION, CRYSTAL-STRUCTURE, AND PROPERTIES OF THE MIXED-VALENCE COMPOUND NB3SE5CL7

被引:17
作者
RIJNSDORP, J [1 ]
JELLINEK, F [1 ]
机构
[1] UNIV GRONINGEN,CTR MAT SCI,ANORGAN CHEM LAB,NL-9747 AG GRONINGEN,NETHERLANDS
关键词
D O I
10.1016/0022-4596(79)90067-7
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The new compound Nb3Se5Cl7 was prepared by heating 2NbSe2Cl2 + 1NbCl4 at 530°C for 2-3 weeks. The compound is monoclinic with a = 7.599, b = 12.675, c = 8.051Å; β = 106.27°; space group P21 m. The corresponding bromide, Nb3Se5Br7 (obtained by decomposition of NbSe2Br2 under NbSeBr3), is isotypic with a = 7.621, b = 12.833, c = 8.069Å; β = 106.21°. from the crystal structure and XPS spectra it follows that Nb3Se5Cl7 can be formulated as: [Nb4+2Nb5+1(Se2)2-2Se2-1Cl-7]. The structure consists of chains of composition [Nb4+2(Se2)2-2Cl-5], to which side chains [Nb5+Se2-Cl-2] are attached. The Nb4+ atoms form pairs (NbNb = 2.94 Å) which explains that Nb3Se5Cl7 is a diamagnetic semiconductor with a band gap (1.59 eV at 5°K, 1.49 eV at 300°K) very similar to that of NbSe2Cl2. © 1979.
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页码:149 / 156
页数:8
相关论文
共 7 条
[1]   X-RAY SCATTERING FACTORS COMPUTED FROM NUMERICAL HARTREE-FOCK WAVE FUNCTIONS [J].
CROMER, DT ;
MANN, JB .
ACTA CRYSTALLOGRAPHICA SECTION A-CRYSTAL PHYSICS DIFFRACTION THEORETICAL AND GENERAL CRYSTALLOGRAPHY, 1968, A 24 :321-&
[2]   X-RAY PHOTOELECTRON-SPECTRA AND ELECTRONIC-STRUCTURE OF ZIRCONIUM TRISULFIDE AND TRISELENIDE [J].
JELLINEK, F ;
POLLAK, RA ;
SHAFER, MW .
MATERIALS RESEARCH BULLETIN, 1974, 9 (06) :845-856
[3]  
PAULING L, NATURE CHEM BOND, P384
[4]  
RIJNSDORP J, 1978, THESIS GRONINGEN
[5]  
Schafer H., 1964, ANGEW CHEM-GER EDIT, V76, P833, DOI DOI 10.1002/ANGE.196407622002
[6]  
Schnering H. G. V., 1966, Z ANORG ALLG CHEM, V347, P231
[7]  
1968, INT TABLES XRAY CRYS, V3, P215