TY - JOUR
T1 - Crystal and molecular structures of the nido-carborane anions, 7,9- and 2,9-C2B9H12-
AU - Fox, Mark A.
AU - Goeta, Andrés E.
AU - Hughes, Andrew K.
AU - Johnson, Andrew L.
PY - 2002/5/23
Y1 - 2002/5/23
N2 - Deboronation of meta-carborane, closo-1,7-C2B10H12, with refluxing piperidine results in the quantitative formation of [(C5H10NH)2H+](nido-7,9-C 2B9H12-) whose structure was determined by X-ray diffraction. Heating under vacuum liberates piperidine to give (C5H10NH2+)(nido-7,9-C 2B9H12-). The reaction of meta-carborane with KOH in refluxing ethanol yields K+ nido-7,9-C2B9H12- and the cage substituted anion 10-EtO-7,9-C2B9H11-. The protonated Proton Sponge salt (PSH+)(nido-7,9-C2B9H12 -) (PS = 1,8-N,N,N′,N′-tetramethylnaphthalenediamine) was obtained by metathesis from the potassium salt, an X-ray crystallographic study located the bridging hydrogen in the anion on the open face between the two adjacent boron atoms. Anaerobic deboronation of para-carborane, closo-1,12-C2B10H12, with KOH in refluxing tetraglyme-toluene gives the potassium salt of nido-2,9-C2B9H12- from which 2,9-C2B9H13 was isolated in 45% yield by protonation. The salt (PSH+)(nido-2,9-C2B9H12 -), obtained from nido-2,9-C2B9H13 and PS, was shown by single crystal X-ray crystallography to contain a hydrogen bridging two boron atoms opposite the carbon atom on the open face. Aerobic deboronation of para-carborane with KOH forms closo-1,10-C2B8H10 and 2-HO-closo-1,10-C2B8H9 in low yields. Fully assigned multinuclear NMR (11B, 13C and 1H) data are reported for the isomeric 7,8-, 7,9- and 2,9-nido-C2B9H12- anions and neutral 7,8- and 2,9-C2B9H13, and compared with computed shifts (at the GIAO B3LYP/6-311G* level) from optimized (at MP2/6-31G*) geometries.
AB - Deboronation of meta-carborane, closo-1,7-C2B10H12, with refluxing piperidine results in the quantitative formation of [(C5H10NH)2H+](nido-7,9-C 2B9H12-) whose structure was determined by X-ray diffraction. Heating under vacuum liberates piperidine to give (C5H10NH2+)(nido-7,9-C 2B9H12-). The reaction of meta-carborane with KOH in refluxing ethanol yields K+ nido-7,9-C2B9H12- and the cage substituted anion 10-EtO-7,9-C2B9H11-. The protonated Proton Sponge salt (PSH+)(nido-7,9-C2B9H12 -) (PS = 1,8-N,N,N′,N′-tetramethylnaphthalenediamine) was obtained by metathesis from the potassium salt, an X-ray crystallographic study located the bridging hydrogen in the anion on the open face between the two adjacent boron atoms. Anaerobic deboronation of para-carborane, closo-1,12-C2B10H12, with KOH in refluxing tetraglyme-toluene gives the potassium salt of nido-2,9-C2B9H12- from which 2,9-C2B9H13 was isolated in 45% yield by protonation. The salt (PSH+)(nido-2,9-C2B9H12 -), obtained from nido-2,9-C2B9H13 and PS, was shown by single crystal X-ray crystallography to contain a hydrogen bridging two boron atoms opposite the carbon atom on the open face. Aerobic deboronation of para-carborane with KOH forms closo-1,10-C2B8H10 and 2-HO-closo-1,10-C2B8H9 in low yields. Fully assigned multinuclear NMR (11B, 13C and 1H) data are reported for the isomeric 7,8-, 7,9- and 2,9-nido-C2B9H12- anions and neutral 7,8- and 2,9-C2B9H13, and compared with computed shifts (at the GIAO B3LYP/6-311G* level) from optimized (at MP2/6-31G*) geometries.
UR - http://www.scopus.com/inward/record.url?scp=0036013808&partnerID=8YFLogxK
U2 - 10.1039/b108937d
DO - 10.1039/b108937d
M3 - Article
AN - SCOPUS:0036013808
SN - 1470-479X
SP - 2132
EP - 2141
JO - Journal of the Chemical Society, Dalton Transactions
JF - Journal of the Chemical Society, Dalton Transactions
IS - 10
ER -