Crystal and Molecular Structure of N,N-Dimethylisopropylideniminium Perchlorate

Trefonas, L. M.; Flurry, R. L.; Majeste, R. J.; Meyers, Edward A.; Copeland, Richard F.

doi:10.1021/ja00962a012

Cited by 31 publications

(21 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formulation of 6 as a cyclic B,N-betaine is justified by the considerable double bond character of the C=N bond. The mean C=N distance5 9f 1.301 A is very similar to the uncorrected value of 1.302 A in the alkylidene iminium ion Me2C=NMe2+ (22). From plots of bond lengths vs. T-bond order, the MO T-bond order of the C=N bonds is estimated as 0.8 (22) ( 1 ) 4 ( 2 ) 1.7(3) C ( l t 0 ( 2 t B ( 1 ) 4 ( 1 ) 37 ( 2 ) 4 ( 4 ) -24.0(3) B ( 2 ) --0 ( 4 t C ( 2 ) 4 ( 1) 2.4(3) C ( 2 t 0 ( 4 t B ( 2 ) 4 ( 3 ) 36.2(2) N ( 2 t 0 ( 3 t B ( 2 ) --0 ( 4 ) -59.1 (2) double bond character in the boron chelates.…”

Section: Resultssupporting

confidence: 74%

Structural studies of organoboron compounds. XXXV. 4,8-Diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia- 2,6-diborata-1,2,3,5,6,7-hexahydronaphthalene

Kliegel¹,

Tajerbashi²,

Rettig³

et al. 1989

Can. J. Chem.

View full text Add to dashboard Cite

. Can. J. Chem. 67, 1644 (1989). The reaction of N,Nf-diethyloxalohydroxamic acid with oxybis(dipheny1borane) yields the title compound. Crystals of 4,8-diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia-2,6-diborata-l,2,3,5,6,7-hexahydronaphthalene are monoclinic, a = 14.3405(9), b = 14.3053(5), c = 14.9301(8) 8,, P = 1 16.136(4)", Z = 4, space group P2, / ! I . ' The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.038 and R , = 0.038 for 3501 reflections with1 2 3u(l). The molecule has a novel bis-six-membered binuclear chelate structure, the Ph'B moieties each being coordinated by (N)O and (C=)O oxygen atoms from different hydroxamate groups. The mean libration-corrected bond distances (C=)&B,

show abstract

Section: Resultssupporting

confidence: 74%

Structural studies of organoboron compounds. XXXV. 4,8-Diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia- 2,6-diborata-1,2,3,5,6,7-hexahydronaphthalene

Kliegel¹,

Tajerbashi²,

Rettig³

et al. 1989

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…From plots of T-bond order vs. bond length for C-N bonds (12,13), these distances have T-bond orders between 0.70 and 0.85. The T-bond order of the C=O bond (1.293(2) A)., estimated to be about 0 .…”

Section: Resultsmentioning

confidence: 99%

Structural studies of organoboron compounds. XLIII. 4-[(1-Hydroxycyclohexyl)methyl]-2,2,5-triphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene

Kliegel¹,

Schumacher²,

Tajerbashi³

et al. 1991

Can. J. Chem.

View full text Add to dashboard Cite

“…It is interesting to note that an orientational disorder even greater than in B has been reported for the cation in the tetragonal (14/mmm, Z = 2) [Me,C=NMe,]C104 (27), in which crystal the ion packing is of the NaC1-type. In this even less constraining environment of nearest C104-neighbours in twofold disorder the cations are situated in mirror planes 11(001), and their orientations are distributed over four symmetry-equivalent C-N directions.…”

Section: Cation Disordermentioning

confidence: 91%

Crystal chemistry of tetraradial species. Part 3. Salts of aliphatic Schiff bases crystallizable from aqueous media: crystal structures of five iminium tetraphenylborates and a 6-31G* ab initio study of simple iminium ions

Knop¹,

Cameron²,

Bakshi³

et al. 1993

Can. J. Chem.

View full text Add to dashboard Cite

. Recrystallization of a primary or secondary alkylammonium tetraphenylborate (TB) from approximately 1 : 1 mixtures of Me2C0 (or MeEtCO) and water yields, against expectation, the TB of the corresponding iminium cation and thus provides an easy route to a variety of aliphatic Schiff bases. The crystal structures of five such salts have been de- are discussed in detail, as also is the tendency of the small iminium ions to orientational disorder. The range of the C=N bond length in these and other iminium salts is quite narrow, with 1.283(12) A as the mean (uncorrected) value. Where a hydrogen atom(s) is attached to the iminium nitrogen, it will form a hydrogen bond (simple or bifurcated) with the aromatic n system of the nearest phenyl ring(s). The narrowness of the C=N bond-length range with respect to substitution on the cation has prompted a detailed 6-31G" ab ir~itio study of the effect, on the geometry of the [H,c=NH,]+ ion, of a partial or complete replacement of the H atoms by one of the following substituents: F, C1, CN, Li, and Na. The 46 structures optimized in planar geometry were supplemented by a number of optimizations of similarly substituted ethylenes as well as by a few optimizations in perpendicular geometry. Analysis of the numerical results involves the bond lengths and angles, Mulliken EM and (in part) Lijwdin EL net charges on the atoms, and electron densities p, = p(r,) at the bond critical points. Only a limited use has been made of comparisons involving the total electronic energies E (substitutional isomerism). Since the above substituents span the entire electronegativity scale, and CN provides for the possibility of conjugation, the effects they produce are expected to bracket the effects that would be produced by any other substituents. The calculations confirm the essential narrowness of the C=N bond-length range in iminium ions. They also show that, at least in the 6-31G:!: scheme, the nitrogen in [H'C=NH,]+ carries a significant negative net charge (both in terms of EM and e,), which is contrary to the conventional representation of the ion as H2C=N+H2. The trends observed in the parameters are smooth and highly self-consistent except for the tri-and tetrasubstituted ions containing Li or Na, where interligand repulsions may invalidate the assumption of planarity. Many of the parameters can be represented to a high degree of correlation as linear functions a, + actzc(X) + aNtl,(X) of the numbers tz of substituent atoms X on the C and N atoms. This representation makes it possible to estimate the contribution to the parameter value from the substitution at the distant atom of the C=N bond, i.e., the extent of localization of the effect produced by the substituent. The success of the linearization of the parameter variation raises the important question of whether the apparent additivity is genuine and intrinsic or merely a property of the 6-31G:': optimization scheme. In other words, will additivity be retained, functionally, for sets of parameters obtained from higher level ab ini...

show abstract

Crystal and Molecular Structure of N,N-Dimethylisopropylideniminium Perchlorate

Cited by 31 publications

References 0 publications

Structural studies of organoboron compounds. XXXV. 4,8-Diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia- 2,6-diborata-1,2,3,5,6,7-hexahydronaphthalene

Structural studies of organoboron compounds. XXXV. 4,8-Diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia- 2,6-diborata-1,2,3,5,6,7-hexahydronaphthalene

Structural studies of organoboron compounds. XLIII. 4-[(1-Hydroxycyclohexyl)methyl]-2,2,5-triphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene

Crystal chemistry of tetraradial species. Part 3. Salts of aliphatic Schiff bases crystallizable from aqueous media: crystal structures of five iminium tetraphenylborates and a 6-31G* ab initio study of simple iminium ions

Contact Info

Product

Resources

About