Structure and bonding in organic derivatives of antimony(V)

The Problem Of Tautomerism

“…This is due to the fairly moderate propensity of silicon to pentacoordination and it, consequently, a result of the transition structure XXIV c. But in other organometallic derivatives of acetylacetone such as antimony [101,102], boron [103], lead and tin [104] derivatives as well as in transition metal-chelate acetylacetonates [105,106], where strong intramolecular coordination exists, the bonds are totally averaged, and symmetrical structures XXV and XXVI are stable. This is due to the fairly moderate propensity of silicon to pentacoordination and it, consequently, a result of the transition structure XXIV c. But in other organometallic derivatives of acetylacetone such as antimony [101,102], boron [103], lead and tin [104] derivatives as well as in transition metal-chelate acetylacetonates [105,106], where strong intramolecular coordination exists, the bonds are totally averaged, and symmetrical structures XXV and XXVI are stable.…”

Triorganoantimony(V) carboxylates: Synthesis, characterization and crystal structure of [Me3Sb(O2C–C5H4N)2]·H2O

“…Their mono-and di-organoantimony(V) complexes are quite often dimeric [1,6] whereas tri-and tetra-organoantimony derivatives are monomeric, with the central metal atom acquiring a trigonal bipyramidal configuration. Anionic bidentate ligands, such as acetylacetonate À , oxinate À (8-hydroxyquinolate ion), Schiff bases, etc., in general, yield hexa-coordinated tri-and tetra-organoantimony complexes [1,7,8].…”

“…Organoantimony(V) complexes containing an Sb-O-R linkage (where OR = alkoxy, phenoxy, carboxylate, oximate) have been investigated in considerable detail [1][2][3][4][5]. Their mono-and di-organoantimony(V) complexes are quite often dimeric [1,6] whereas tri-and tetra-organoantimony derivatives are monomeric, with the central metal atom acquiring a trigonal bipyramidal configuration.…”

Synthesis, spectroscopic and structural aspects of triphenylantimony(V) complex with internally functionalized acetylferroceneoxime: Crystal and molecular structures of [C5H5FeC5H4C(CH3)NO]2SbPh3 and C5H5FeC5H4C(CH3)NOH

“…The chemistry of antimony complexes derived from oximes have been an active area of research for more than two decades [1][2][3][4], not only for the striking structural possibilities ranging from discrete monomeric structures to supramolecular assemblies [5], but also for the biological importance [6] in antimicrobial properties [7] as well as antitumor activities [8,9]. Of many multidentate organic ligands, oximes were of particular importance, which were generally weak acids that could form numerous salts and complexes quite readily [10].…”

“…Triorganoantimony(V) complex (C 5 H 5 FeC 5 H 4 C(CH 3 )@NO) 2 SbPh 3 (1) has been prepared by the reaction of Ph 3 SbCl 2 with acetylferroceneoxime C 5 H 5 FeC 5 H 4 C(CH 3 )@NOH (2) in 1:2 molar ratio in anhydrous toluene. The complexes have been characterized by elemental analyses, IR and NMR ( 1 H and 13 C) spectroscopic studies, and biologic activity was measured.…”