Chemistry:Phosphorus selenide
Phosphorus selenides are a relatively obscure group of compounds. There have been some studies of the phosphorus - selenium phase diagram and the glassy amorphous phases are reported. The compounds that have been reported are shown below. While some of phosphorus selenides are similar to their sulfide analogues, there are some new forms, molecular P
2Se
5 and the polymeric catena-[P
4Se
4]
x. There is also some doubt about the existence of molecular P
4Se
10.
Crystallographically confirmed compounds
P
2Se
5
Molecular P
2Se
5 has a norbornane like structure with two phosphorus atoms with oxidation state +3 bridged by two diselenide units (–Se–Se–, analogous to disulfide) and one selenide unit (–Se–).[1] It was isolated by solvent (CS
2) extraction from a P
2Se
5 amorphous phase made from the elements.[2]
P
4Se
3
P
4Se
3 has been characterised crystallographically and has the same structure as the low temperature form of P
4S
3.[3] It can be prepared from the elements. One preparation is to extract and recrystallise using tetralin.
P
4Se
5
The P
4Se
5 molecule has the same structure as P
4S
5.[4] It was prepared by reacting P
4Se
3 with bromine in CS
2.
catena-[P
4Se
4]
x
This compound consists of polymeric chains of norbornane-like units joined by Se atoms.[5] As each P atom in the repeat unit is bonded to another P atom and to two Se atoms, each P atom has a formal oxidation state of +2.
Compounds confirmed spectroscopically
P
4Se
4
P
4Se
4 has two crystalline forms α-P
4Se
4 with the same molecular structure as α-P
4S
4 and β-P
4Se
4 with same molecular structure as β-P
4S
4.[6] A fully characterised compound (CuI)
3P
4Se
4 contains P
4Se
4 with a β-P
4S
4 structure.[7]
P
4Se
7
This has been reported to have the same structure as P
4S
7.[8][9] One well-known textbook does not mention it at all.[10]
P
4Se
10
Molecular P
4Se
10 has been reported to share the same structure as P
4S
10 and P
4O
10,[8][9][11] but one well-known textbook does not mention it at all.[10] A review (2001) examining P-Se amorphous phases did not confirm the presence of molecular P
4Se
10.[12] The isoelectronic anion [Ge
4Se
10]4− which has the adamantane like P
4O
10 structure is known, an example is the sodium salt Na
4[Ge
4Se
10].[13]
Other compounds
P
4Se
6, P
14Se, P
4Se, P
4Se
2, P
2Se, have been reported.[8]
Phosphorus - selenium glasses
Phosphorus - selenium glasses have been examined using 31P-NMR and Raman spectroscopy. Glasses are formed in P
xSe
1-x over the range of compositions 0 < x < 0.8 with a small window around 0.52 – 0.60 centred on 0.57 (corresponding to the compound P
4Se
3) where there is a tendency to crystallise. For x < 0.47 the glasses contain Se
n chain fragments, pyramidal P units (P oxidation state +3), quasi-tetrahedral P units (P oxidation state +5, with P=Se double bond) and P
2 units (P in formal oxidation state +4). There is no evidence for an amorphous phase containing molecular P
4Se
10.[12]
References
- ↑ Blachnik, R.; Lönnecke, P.; Boldt, K.; Engelen, B. (1994). "P2Se5". Acta Crystallographica Section C 50 (5): 659–661. doi:10.1107/S0108270193010534. ISSN 0108-2701.
- ↑ Blachnik, Roger; Lönnecke, Peter (1992). "From P4Se3I2via P3Se4I to P2Se5". Phosphorus, Sulfur, and Silicon and the Related Elements 65 (1–4): 103–106. doi:10.1080/10426509208055329. ISSN 1042-6507.
- ↑ Keulen, E.; Vos, A. (1959). "The crystal structure of P4Se3". Acta Crystallographica 12 (4): 323–329. doi:10.1107/S0365110X59000950. ISSN 0365-110X.
- ↑ Penney, G. J.; Sheldrick, G. M. (1971). "Crystal and molecular structure of tetraphosphorus pentaselenide". Journal of the Chemical Society A: Inorganic, Physical, Theoretical: 245. doi:10.1039/j19710000245. ISSN 0022-4944.
- ↑ Ruck, Michael (1994). "Darstellung und Kristallstruktur des ersten polymeren Phosphorselenidscatena-(P4Se4)x". Zeitschrift für Anorganische und Allgemeine Chemie 620 (10): 1832–1836. doi:10.1002/zaac.19946201028. ISSN 0044-2313.
- ↑ Blachnik, R.; Lönnecke, P.; Nuß, J. (1994). "Neues vom P4Se4". Zeitschrift für Anorganische und Allgemeine Chemie 620 (1): 160–166. doi:10.1002/zaac.19946200126. ISSN 0044-2313.
- ↑ Pfitzner, A.; Reiser, Sara (1999). "(CuI)3P4Se4: β-P4Se4Cages between Columns of Copper Iodide†". Inorganic Chemistry 38 (10): 2451–2454. doi:10.1021/ic981042f. ISSN 0020-1669. https://epub.uni-regensburg.de/11784/1/49_%28CuI%293P4Se4%20b-P4Se4%20Cages%20between%20Columns%20of%20Copper%20Iodide.pdf.
- ↑ 8.0 8.1 8.2 Corbridge, D.E.C (2013). Phosphorus: Chemistry, Biochemistry and Technology. CRC Press, Taylor Francis Group. p. 808. ISBN 978-1-4398-4088-7.
- ↑ 9.0 9.1 Handbook of Chalcogen Chemistry –New Perspectives in Sulfur, Selenium and Tellurium. Royal Society of Chemistry. 2007. ISBN 9780854043668.
- ↑ 10.0 10.1 Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils, ed., Inorganic Chemistry, San Diego/Berlin: Academic Press/De Gruyter, ISBN 0-12-352651-5
- ↑ Housecroft, Catherine E; Sharpe, Alan G (2005). Inorganic Chemistry (2d ed.). Pearson education. pp. 427. ISBN 978-0-13-039913-7.
- ↑ 12.0 12.1 Georgiev, D.; Mitkova, M.; Boolchand, P.; Brunklaus, G.; Eckert, H.; Micoulaut, M. (2001). "Molecular structure, glass transition temperature variation, agglomeration theory, and network connectivity of binary P-Se glasses". Physical Review B 64 (13): 134204. doi:10.1103/PhysRevB.64.134204. ISSN 0163-1829. Bibcode: 2001PhRvB..64m4204G.
- ↑ Eisenmann, B.; Hansa, J. (1993). "Crystal structure of tetrasodium decaselenotetragermanate, Na4[Ge4Se10]". Zeitschrift für Kristallographie 205 (Part-2): 325–326. doi:10.1524/zkri.1993.205.Part-2.325. ISSN 0044-2968. Bibcode: 1993ZK....205..325E.
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