NOE and PGSE NMR Spectroscopic Studies of Solution Structure and Aggregation in Metallocenium Ion-Pairs

Journal of the American Chemical Society

Volumn 126, Issue 5, 2004, Pages 1448-1464

  Zuccaccia, Cristiano ^a,b   Stahl, Nicholas G ^a   Macchioni, Alceo ^a   Chen, Ming Chou ^a   Roberts, John A ^a   Marks, Tobin J ^a  

^a NORTHWESTERN UNIVERSITY   (United States)

^b UNIVERSITY OF PERUGIA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

AGGREGATES; BENZENE; CATALYSTS; NUCLEAR MAGNETIC RESONANCE; ORGANIC SOLVENTS; PERMITTIVITY; ZIRCONIUM;

INTERIONIC STRUCTURES; SOLUTION STRUCTURES;

POLYMERIZATION;

BENZENE; BIPHENYL DERIVATIVE; BORANE DERIVATIVE; CATION; FLUOROALUMINATE; METAL ION; POLYETHYLENE; TOLUENE; TRIS(2,2',2'' NONAFLUOROBIPHENYL)FLUOROALUMINATE; TRIS(2,2'2'' NONAFLUOROBIPHENYL)BORANE; UNCLASSIFIED DRUG; ZIRCONIUM;

AQUEOUS SOLUTION; ARTICLE; CATALYST; CONCENTRATION RESPONSE; CRYSTAL STRUCTURE; DIFFUSION COEFFICIENT; HYDRODYNAMICS; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; NUCLEAR OVERHAUSER EFFECT; POLYMERIZATION; SOLID STATE; TEMPERATURE; X RAY DIFFRACTION;

EID: 1042299850     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja0387296     Document Type: Article

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133. Note that these NOESY spectra were recorded with a 6 s relaxation delay, 150 ms mixing time, and 32 scans per increment. If the parameters routinely used for small molecule NOESY experiments (namely 1s relaxation delay, 800 ms mixing time, and 16 scans per increment) are employed, the B-Me/ H1 cross-peak is hardly visible. This is likely a consequence of the rapid B-Me relaxation time in combination with the expectation of very little NOE enhancement.
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144. The higher stability of compound 10 in toluene could be due in principle to either (1) a higher intrinsic stability due to coordination of toluene instead of benzene (see, for example: Hayes, P. G.; Piers, W. E.; Paervez, M. J. Am. Chem. Soc. 2003, 125, 5622) or (2) a lower level of aggregation that impedes possible bimolecular decomposition pathways (see, for example: Li, L.; Hung, M.; Xue, Z. J. Am. Chem. Soc. 1995, 117, 12746) or, more likely, (3) a combination of 1 and 2.
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146. - (FPBB = tris(2,2′,2″ -nonafluorobiphenyl)fluoroborate, (unpublished results from this laboratory), suggesting that the central atom (B versus Al) plays a fundamental role.
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