Preparation, characterization, and stereochemistry of binuclear vanadyl(IV) monomethyl- and dimethyltartrate(4-) complexes and the crystal structure of tetrasodium (. mu. -(+)-dimethyltartrato(4-))-(. mu. -(-)-dimethyltartrato(4-))-bis(oxovanadate(IV)) dodecahydrate

Journal Article · Mon Feb 01 00:00:00 EST 1982 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00132a039· OSTI ID:5690257

Hahs, S K; Ortega, R B; Tapscott, R E; Campana, C F; Morosin, B

The syntheses and characterizations (by ESR, IR, and electronic spectroscopies) of the sodium salts of the DL and DD (or LL) binuclear complexes of vanadyl(IV) with dimethyltartrate(4-), dmt, and with monomethyltartrate(4-), mmt, are described. Na/sub 4/((VO)/sub 22/((+)-dmt)((-)-dmt)) exists in two crystal forms - a blue dodecahydrate and a pink hexahydrate. An x-ray diffraction study of the former shows that the V-V distance (3.429 (3) A) of the binuclear anion is decreased relative to that of the unsubstituted tartrate(4-), tart, complex, as predicted from earlier ESR studies, and that this decrease is due in part to a dropping of the vanadium atom into the plane of the four coordinating equatorial oxygen atoms. A sixth oxygen atom is weakly coordinated (2.377 (3) A) trans to the vanadyl oxygen atom. A purple tetradecahydrate also obtained with racenic dmt contains a mixture of ((VO)/sub 2/ ((+)-dmt)/sub 2/)/sup 4 -/ and ((VO)/sub 2/((-)-dmt)/sub 2/)/sup 4 -/). The aqueous solution ligand-exchange reaction between the DD and LL complexes of this salt to give the more stable DL isomer is remarkably slow (several hours at room temperature). Stereoselective effects allow the production of mixed-ligand species containing two of the three ligands tart, dmt, and mmt, and potentiometric titrations indicate a decreasing stability of the DL isomer (relative to the DD and LL isomers) as methyl substitution increases.

• Research Organization: Univ. of New Mexico, Albuquerque
• OSTI ID: 5690257
• Journal Information: Inorg. Chem.; (United States), Vol. 21:2
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
SODIUM COMPOUNDS
CRYSTAL STRUCTURE
SYNTHESIS
TARTRATES
VANADIUM COMPLEXES
BOND ANGLE
ELECTRON SPECTRA
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
HYDRATES
INFRARED SPECTRA
INTERATOMIC DISTANCES
ISOMERS
LIGANDS
POTENTIOMETRY
STEREOCHEMISTRY
X-RAY DIFFRACTION
ALKALI METAL COMPOUNDS
CARBOXYLIC ACID SALTS
COHERENT SCATTERING
COMPLEXES
DATA
DIFFRACTION
DISTANCE
INFORMATION
MAGNETIC RESONANCE
NUMERICAL DATA
RESONANCE
SCATTERING
SPECTRA
TITRATION
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)