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(Benzene‐1,3,5‐triyl)tris[phosphine] (C 6 H 3 (PH 2 ) 3 ) and (Benzene‐1,3,5‐triyl)tris[phosphonic Acid] (C 6 H 3 [P(O)(OH) 2 ] 3 ). Absence of Hydrogen Bonding in Solid Primary Phosphines
Author(s) -
Reiter Stephan A.,
Assmann Bernd,
Nogai Stefan D.,
Mitzel Norbert W.,
Schmidbaur Hubert
Publication year - 2002
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(200204)85:4<1140::aid-hlca1140>3.0.co;2-x
Subject(s) - phosphine , chemistry , tris , phosphonate , benzene , tetrahydrofuran , medicinal chemistry , solvent , phenylene , organic chemistry , polymer chemistry , catalysis , polymer , biochemistry
The prolonged photo‐ Arbuzov reaction (3 weeks, Hg lamp) of 1,3,5‐trichloro‐benzene with a large excess of trimethyl phosphite (as a solvent) at 50° gives moderate yields of dimethyl (3,5‐dichlorophenyl)phosphonate ( 1 ; 14.5%), tetramethyl (5‐chloro‐1,3‐phenylene)bis[phosphonate] ( 2 ; 35.4%), and hexamethyl (benzene‐1,3,5‐triyl)tris[phosphonate] ( 3 ; 30.1%). The products can be separated by fractional distillation. Acid hydrolysis of the esters gives almost quantitative yields of the corresponding phosphonic acids 4 – 6 . Reduction of the esters 1 – 3 by LiAlH 4 in tetrahydrofuran affords the primary phosphines (3,5‐dichlorophenyl)phosphine ( 7 ; 46.5%), (5‐chloro‐1,3‐phenylene)bis[phosphine] ( 8 ; 34.5%) and (benzene‐1,3,5‐triyl)tris[phosphine] ( 9 ; 25.2% yield). In the crude reduction products from 2 (preparation of 8 ) and from 3 (preparation of 9 ), (3‐chlorophenyl)phosphine and (1,3‐phenylene)bis[phosphine], respectively, are observed as by‐products. All compounds are characterized by standard analytical, spectroscopic, and (for 1, 7 , and 8 ) structural techniques. The arrangement of the molecules in the crystal structures of 7 and 8 suggest that H‐bonding between the primary aryl phosphines is virtually insignificant for the packing of the components. This is in marked contrast to the importance of H‐bonding for the supramolecular chemistry of aryl amines. The new primary polyphosphines and polyphosphonic acids are to be employed in the construction of extended arrays.