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Reactions and Coordination Properties of the First Secondary Carbaboranyldiphosphane: 1,2‐Bis(phenylphosphanyl)‐1,2‐dicarba‐ closo ‐dodecaborane(12)
Author(s) -
Balema Viktor P.,
Somoza, Jr. Fernando,
HeyHawkins Evamarie
Publication year - 1998
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199805)1998:5<651::aid-ejic651>3.0.co;2-d
Subject(s) - chemistry , toluene , carborane , boiling , medicinal chemistry , yield (engineering) , nuclear magnetic resonance spectroscopy , norbornadiene , stereochemistry , organic chemistry , catalysis , materials science , metallurgy
When a mixture of stereoisomers of rac ‐ and meso ‐1,2‐bis(phenylphosphanyl)‐1,2‐dicarba‐ closo ‐dodecaborane(12) ( 1a , b ; 1a / 1b = 3:1) is treated with [Cp 2 ZrMe 2 ] in boiling toluene for 2 h, the formation of three phosphorus‐containing products, namely meso ‐[Cp 2 Zr(PPh) 3 ] ( 3 ), (PPh) 4 ( 4 ) and (PPh) 5 ( 5 ), ratio 2.8:1.1:1.0, was observed by 31 P‐NMR spectroscopy. In the 11 B‐NMR spectrum of the reaction mixture, only signals for 1,2‐dicarba‐ closo ‐dodecaborane(12) were observed. When zirconocene, prepared in situ from [Cp 2 ZrCl 2 ] and BuLi, was treated with 1a , b at low temperature and then heated to reflux in toluene for 2 h, only formation of 3 and 1,2‐dicarba‐ closo ‐dodecaborane(12) was observed. The mixture of stereoisomers of 1a , b reacts with CuCl in THF to give rac ‐ and meso ‐[CuCl(THF){1,2‐(PHPh) 2 C 2 B 10 H 10 }] ( 7a , b ), which is only stable in THF solution and loses THF in vacuo over several hours to yield the insoluble colorless complex [CuCl{1,2‐(PHPh) 2 C 2 B 10 H 10 }] n ( 8 ). In THF solution, 7 reacts with PPh 3 to give the stable isolable complex [CuCl(PPh 3 ){1,2‐(PHPh) 2 C 2 B 10 H 10 }] ( 9 ). No reaction of 1a , b is observed with [Cp′Mo(CO) 3 ] 2 (Cp′ = C 5 H 4 Me) in boiling THF, while only decomposition occurs in boiling toluene. However, [(NBD)Mo(CO) 4 ] (NBD = norbornadiene) reacts smoothly with 1a in toluene at room temperature to give cis ‐ rac ‐[Mo(CO) 4 {1,2‐(PHPh) 2 C 2 B 10 H 10 }] ( 10 ). Compounds 7 , 9 , and 10 were characterized spectroscopically ( 1 H, 31 P, 11 B, 13 C NMR, IR), and an X‐ray structure determination was carried out on 10 .