Triphenylphosphine oxide
Structural formula | ||||||||||||||||
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General | ||||||||||||||||
Surname | Triphenylphosphine oxide | |||||||||||||||
other names |
Triphenylphosphine oxide |
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Molecular formula | C 18 H 15 OP | |||||||||||||||
Brief description |
white to yellowish solid with an unpleasant odor |
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External identifiers / databases | ||||||||||||||||
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properties | ||||||||||||||||
Molar mass | 278.29 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
1.2 g cm −3 |
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Melting point |
155-158 ° C |
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boiling point |
> 360 ° C |
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solubility |
bad in water |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Triphenylphosphine oxide , outdated triphenylphosphine oxide, is an organic phosphorus compound . It consists of a phosphorus atom to which three phenyl radicals and an oxidic oxygen are bound.
Manufacturing
In organic chemistry, triphenylphosphine oxide is formed in stoichiometric amounts as an unavoidable “waste product” in the Wittig reaction when a carbonyl compound - aldehyde or ketone - is reacted with a phosphorylide with three phenyl groups attached to its phosphorus atom. It is often also formed as a by-product in other reactions in which triphenylphosphine or derivatives thereof are used, such as in the Appel reaction , the Staudinger reaction or the Mitsunobu reaction .
It can be prepared by oxidation of triphenylphosphane are prepared with oxygen, which is why triphenylphosphine after prolonged standing still contains a portion of triphenylphosphine oxide.
properties
Triphenylphosphine oxide is a colorless solid that melts at 155–158 ° C. It is poorly soluble in water, cyclohexane , carbon tetrachloride and acetonitrile . However, it is readily soluble in dichloromethane , chloroform and short-chain alcohols such as methanol , ethanol and 1-propanol .
The central phosphorus atom is tetrahedrally coordinated . In the energetically most favorable conformation , the phenyl radicals are twisted against each other.
Triphenylphosphine oxide is a good ligand for hard metal centers.
The compound decomposes at higher temperatures. The specified decomposition temperature with the criterion of a decomposition rate of 1 mol% h −1 is 454 ° C.
Triphenylphosphine oxide also plays a role when sniffing out data carriers (memory chips, etc.) by sniffer dogs.
Individual evidence
- ↑ a b c d e f g h Entry for CAS no. 791-28-6 in the GESTIS substance database of the IFA , accessed on April 25, 2011(JavaScript required) .
- ^ E. Maccarone, G. Perrini, Gazz. Chim. Ital. 1982 , 112 , 447-454.
- ^ DML Goodgame, M. Goodgame: Near-Infrared Spectra of Some Pseudotetrahedral Complexes of Cobalt (II) and Nickel (II) , Inorg. Chem. 1965 , 4 , 139-143.
- ↑ Johns, IB; McElhill, EA; Smith, JO: Thermal Stability of Some Organic Compounds in J. Chem. Eng. Data 7 (1962) 277-281, doi : 10.1021 / je60013a036 .
- ↑ Sniffer dogs sniff out data. Retrieved November 17, 2019 .