DC Field | Value | Language |
---|---|---|
dc.contributor.author | Park, JE | ko |
dc.contributor.author | Bae, BJ | ko |
dc.contributor.author | Kim, Y | ko |
dc.contributor.author | Park, Joon Taik | ko |
dc.contributor.author | Suh, IH | ko |
dc.date.accessioned | 2013-03-02T20:09:31Z | - |
dc.date.available | 2013-03-02T20:09:31Z | - |
dc.date.created | 2012-02-06 | - |
dc.date.created | 2012-02-06 | - |
dc.date.issued | 1999-03 | - |
dc.identifier.citation | ORGANOMETALLICS, v.18, no.6, pp.1059 - 1067 | - |
dc.identifier.issn | 0276-7333 | - |
dc.identifier.uri | http://hdl.handle.net/10203/75293 | - |
dc.description.abstract | The reactions of R3Al (R = Me, Et) with N,N-dimethylethylenediamine (DMEDA) in a 1:1 molar ratio produce adducts, R3Al . NH2C2H4NMe2 (1a, R = Me; Ib, R = Et), which upon heating in refluxing toluene result in alkane elimination to afford the chelated monomers R2AlNHC2H4NMe2 (2a, R = Me; 2b, R = Et), respectively. Compounds 2a,b form adducts with 1 equiv of R3Al through the 3-coordinate nitrogen atom to produce R3AlN(H)C2H4NMe2AlR2 (3a, R = Me; 3b, R = Et), which can be alternatively prepared by the reaction of R3Al with DMEDA in a 2:1 molar ratio by alkane elimination at room temperature. Thermolysis of 3a,b at 140 degrees C in sealed ampules produces a mixture of cis and trans isomers of tetrametallic imidoalanes, [R2Al(mu-NC2H4NMe2AlR2)](2) (4a, R = Me; 4Cb, R = Et). Slow recrystallization of the isomeric mixture affords crystals of only the cis isomer for both 4a and 4b, but in solution cis-4a and cis-4b equilibrate with the respective trans isomers. The cis --> trans isomerization of 4a has been studied by H-1 NMR spectroscopy. The equilibrium has been observed to follow reversible first-order kinetics with Delta H degrees = 1.67 +/- 0.60 kJ mol(-1) and Delta S degrees = 9.07 +/- 2.80 J mol(-1) K-1. The activation parameters for the cis --> trans conversion are Delta H-1 = 125.8 +/- 9.3 kJ mol(-1) and Delta S-1 = 89.7 +/- 1.2 J mol(-1) K-1, and those for the reverse process are Delta H-1 = 124.2 +/- 9.3 kJ mol(-1) and Delta S-1 = 80.7 +/- 1.2 J mol(-1) K-1. Pyrolysis of 4a,b in the presence of 2 equiv of DMEDA at 190 degrees C in sealed ampules gives hexameric imidoalanes, (RAlC2H4NMe2)(6) (5a, R = Me; 5b, R = Et), by alkane elimination. Compounds 5a,b can be also prepared by pyrolysis of 2a,b under similar conditions, but in lower yields. The molecular structures of cis-4b and 5b have been determined by single-crystal X-ray diffraction. The molecular geometry of cis-4b involves one four-membered Al2N2 ring and two five-membered AlN2C2 rings of cis conformation, and it has approximate C-2 symmetry with the C-2 axis going through the center of the Al2N2 ring. The hexameric imidoalane 5b consists of a hexagonal prism of the (AlN)(6) cage formed by two flat six-membered (AlN)(3) rings linked together by six transverse Al-N bonds. | - |
dc.language | English | - |
dc.publisher | AMER CHEMICAL SOC | - |
dc.subject | CIS-TRANS ISOMERIZATION | - |
dc.subject | MAGNETIC-RESONANCE SPECTRA | - |
dc.subject | MOLECULAR-STRUCTURE | - |
dc.subject | SILYLAMIDO COMPLEXES | - |
dc.subject | CRYSTAL-STRUCTURES | - |
dc.subject | ALUMINUM NITRIDE | - |
dc.subject | CHEMISTRY | - |
dc.subject | STEREOCHEMISTRY | - |
dc.subject | POLY(N-ALKYLIMINOALANES) | - |
dc.subject | COORDINATION | - |
dc.title | Reactions of AlR3 (R = Me, Et) with H2NCH2CH2NMe2: Synthesis and characterization of amido- and imidoalanes | - |
dc.type | Article | - |
dc.identifier.wosid | 000079256000017 | - |
dc.identifier.scopusid | 2-s2.0-0000101804 | - |
dc.type.rims | ART | - |
dc.citation.volume | 18 | - |
dc.citation.issue | 6 | - |
dc.citation.beginningpage | 1059 | - |
dc.citation.endingpage | 1067 | - |
dc.citation.publicationname | ORGANOMETALLICS | - |
dc.contributor.localauthor | Park, Joon Taik | - |
dc.contributor.nonIdAuthor | Park, JE | - |
dc.contributor.nonIdAuthor | Bae, BJ | - |
dc.contributor.nonIdAuthor | Kim, Y | - |
dc.contributor.nonIdAuthor | Suh, IH | - |
dc.type.journalArticle | Article | - |
dc.subject.keywordPlus | CIS-TRANS ISOMERIZATION | - |
dc.subject.keywordPlus | MAGNETIC-RESONANCE SPECTRA | - |
dc.subject.keywordPlus | MOLECULAR-STRUCTURE | - |
dc.subject.keywordPlus | SILYLAMIDO COMPLEXES | - |
dc.subject.keywordPlus | CRYSTAL-STRUCTURES | - |
dc.subject.keywordPlus | ALUMINUM NITRIDE | - |
dc.subject.keywordPlus | CHEMISTRY | - |
dc.subject.keywordPlus | STEREOCHEMISTRY | - |
dc.subject.keywordPlus | POLY(N-ALKYLIMINOALANES) | - |
dc.subject.keywordPlus | COORDINATION | - |
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