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[(C 5 H 5 )Co{P(O)(OH) 2 } 3 H]: A Novel Organometallic Tris‐phosphonic Acid That Dissolves Glass to Form a Six‐Coordinate Silicon Complex
Author(s) -
Kläui Wolfgang,
Mocigemba Nicole,
WeberSchuster Annette,
Bell Ralf,
Frank Walter,
Mootz Dietrich,
Poll Wolfgang,
Wunderlich Hartmut
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20020517)8:10<2335::aid-chem2335>3.0.co;2-p
Subject(s) - chemistry , ligand (biochemistry) , medicinal chemistry , hydrogen bond , crystal structure , tris , inorganic chemistry , chloride , molecule , sodium , intramolecular force , crystallography , stereochemistry , organic chemistry , biochemistry , receptor
Abstract The sodium salt of the tripodal oxygen ligand Na[(C 5 H 5 )Co{P(O)(OMe) 2 } 3 ] ( 1 ) reacts with gaseous hydrogen chloride in dichloromethane to give sodium chloride and [(C 5 H 5 )Co{P(O)(OMe) 2 } 3 H 2 ]Cl ( 2 ). Addition of an equimolar amount of 1 leads to precipitation of sodium chloride again to yield the acid form of the ligand [(C 5 H 5 )Co{P(O)(OMe) 2 } 3 H] ( 3 ). Its solid‐state structure contains a very short intramolecular OH ⋅⋅⋅ O hydrogen bond. The compound hydrolyses in boiling water to give methanol and the title complex [(C 5 H 5 )Co{P(O)(OH) 2 } 3 H] ( 4 ). This complex is a rather strong tris‐phosphonic acid (p K a 12.0, p K a 24.0, p K a 36.3, and p K a 49.6). Attempts to grow single crystals of this highly water‐soluble yellow crystalline compound lead to the silicon complex [{(C 5 H 5 )Co[P(O)(OH) 2 ] 2 [P(O) 2 (OH)]} 2 Si] ⋅ 8 H 2 O ( 5 ). The crystal structure determination shows that it is a molecular complex of two tris‐phosphonic acids that each act as a tris‐chelating ligand. Additional water molecules form a complex net of hydrogen bonds between the complexes of 5 . The SiO 6 octahedron is only insignificantly distorted with Si−O bond lengths of 1.78 Å. Complex 4 reacts with stoichiometric amounts of potassium carbonate to yield the potassium salt K[(C 5 H 5 )Co{P(O)(OH) 2 } 3 ] ( 6 ). The crystal structure of 6 has also been determined. In the solid state it is a two‐dimensional coordination polymer with each potassium ion being coordinated by twelve oxygen atoms of six tris‐phosphonic acids.