Preparation and NMR spectra of PF4(N-N)+ and SiF4(N-N), where N-N = 2,2′-bipyridine, 4-fluoro-2,2′-bipyridine, and 1,10-phenanthroline

Nguyen, Tuan Quang; Qu, Fengli; Huang, I-Der; Janzen, A. F.

doi:10.1139/v92-265

Cited by 27 publications

(30 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[I], while greater hydrogen bonding between ammonia molecules increases the concentration of the hydrogen-bonded intermediate, eq. [2], and thereby reduces slightly the overall rate of formation of H,N:BF,, as compared to Me-NH,:BF,. Statistical factors (16) related to the number of equivalent pathways by which H--N or H--F bonds can be formed were not included in our calculation, but they would also favour the ammonia intermediates and further reduce the overall rate of formation of the ammonia adduct, as compared to the methylamine adduct, in agreement with experiment.…”

Section: Resultsmentioning

confidence: 99%

“…Concentration of (py)(Me,N)BF,+ after 1 X 1 0 -~s is 1.7 X IO-~OM. mental bond strength data prevents a realistic test of this suggestion, although selective cleavage of fluorine-bridging bonds has been described for related systems (1,2,20).…”

Section: I-mentioning

confidence: 99%

“…where N-N is bipyridine, 4-fluorobipyridine. and phenanthroline (2), but the simulation of a more complex pathway that includes protonation and deprotonation steps is beyond the capacity of our kinetic program, although analogous systems have been studied by NMR in which protonation-deprotonation is coupled to a rapid 5-center step, e.g., the base-RIP-(O)OC(CF,),C(CF,),OH system (24).…”

Section: I-mentioning

confidence: 99%

See 2 more Smart Citations

The boron trifluoride – base system: application of the coordination model of reaction mechanisms

Ou¹,

Wallace²,

Janzen³

1993

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

. Can. J. Chem. 71, 51 (1993). The mechanism of reaction of boron trifluoride with amines, dialkyl ethers, and pyridine has been analyzed on the basis of the coordination model of reaction mechanisms. This model is tested mathematically by carrying out kinetic simulations of pathways P(X,C), accompanied by the calculation of structures of postulated intermediates by GAUSSIAN86 methods. Analyses of reaction mechanisms, including calculation of concentration vs. time curves, are reported for the following systems: NH3-BF,, MeNH2-BF,, Me20-Et20-BF,, Me20-Et20:BF3, pyridine-BF3, pyridine-Me3N-BF3, F3B:N-N:BF3, and (N-N)BF2+. XIAOBO Ou, ROBERT WALLACE et ALEXANDER F. JANZEN. Can. J . Chem. 71, 51 (1993). Faisant appel au modkle de coordination des mkcanismes rkactionnels, on a analysk le mecanisme reactionnel du trifluorure de bore avec les amines, les ethers dialkylks et la pyridine. On a kvaluk le modkle d'une faqon mathematique en effectuant des simulations cinktiques des diverses voies rkactionnelles P(X,C), tout en calculant les structures des intermkdiaires prksumks par des methodes gaussiennes-86. On rapporte des analyses des mkcanismes reactionnels, y compris des calculs de concentration vs. temps, pour les systkmes suivants : NH3-BF3, MeNH2-BF3, Me20-Et20-BF,, Me,OEt,0:BF3, pyridine-BF3, pyridine-Me3N-BF,, F3B:N-N:BF3 et (N-N)BF,+.[Traduit par la rkdaction]The coordination model of reaction mechanisms (1-3) describes in a formal way the discrete changes in coordination number and electron count of individual atoms and reDresents the connectivity of atoms in multistep pathways in graphical form as pathway P(x,c)., In this paper we wish to describe a mathematical test of the coordination model by comparing calculated results with extensive experimental data that are available for the reactions of boron trifluoride with Lewis bases (4-6). The model assumes that intermolecular steps, + C , are limited by the rate of diffusion and that steps which decrease the coordination number, -C and -Cc, are slower and depend on the strength of the bond that is cleaved, but cyclic intramolecular n-center steps, +C', are statistically favoured, particularly in the case of 3-, 4-, 5-, and 6-center steps. Kinetic simulation of pathways P(X,C) is carried out by associating elementary rate constants with the four coordination number operators +C, -C, +Cc, and -Cc, while molecular orbital calculations are helpful in estimating relative rate constants for intermediates where experimental data are not available.Any mechanistic description of the BF,-base system must accommodate the f o l l o w~n~ experimental facts: (a) the formation of base:BF3 is a bimolecular process with rate constants in the range 1 0~-1 0~~ M-' s-' (7); (b) rates of reaction 'Presented at the 203rd ACS National Meeting, San Francisco, April 5-10, 1992. '~u t h o r to whom correspondence may be addressed. 3~otation: A graph P(X,C) consists of a vertex set X of reactants, intermediates, and products, and an edge set C of coordination number operators +c, -C, ...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: I-mentioning

confidence: 99%

Section: I-mentioning

confidence: 99%

See 1 more Smart Citation

The boron trifluoride – base system: application of the coordination model of reaction mechanisms

Ou¹,

Wallace²,

Janzen³

1993

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, the signal of HÀC(5') of 19 was observed as ddd at d 7.17, while the signal of HÀC(5''') of 20 was shifted to low field and observed at d 7.32. The methoxy and methylene groups, both, were observed at d 3.78 (19) and 3.81 (20), respectively.…”

Section: Methodsmentioning

confidence: 99%

“…In a typical reaction, 4-nitro-2,2'-bipyridine (21) [20] in DMF was converted to the unsymmetrical 4-azido-2,2'-bipyridine (22) [9] (IR: 2108 cm À1 (-N 3 )) in 70% yield (Scheme 5). Irradiation of 22 in MeOH/dioxane under basic conditions resulted in two main products which were separated by chromatography (silica gel) and identified by their spectra as 23 (34%) and 2,2'-bipyridin-4-amine [20] (30%).…”

Section: Methodsmentioning

confidence: 99%

Photochemical and Thermal Reactions of Azido-oligopyridines: Diazepinones, a New Class of Metal-Complex Ligands

Fallahpour

2000

HCA

View full text Add to dashboard Cite

show abstract

Photoinduced Processes within Compact Dyads Based on Triphenylpyridinium‐Functionalized Bipyridyl Complexes of Ruthenium(II)

Lainé

Ciofini

Ochsenbein

et al. 2005

Chemistry A European J

View full text Add to dashboard Cite

As an alternative to conventional charge-separation functional molecular models based on long-range ET within redox cascades, a "compact approach" has been examined. To this end, spacer elements usually inserted between main redox-active units within polyad systems have been removed, allowing extended rigidity but at the expense of enhanced intercomponent electronic communication. The molecular assemblies investigated here are of the P-(theta (1))-A type, where the theta (1) twist angle is related to the degree of conjugation between the photosensitizer (P, of {Ru(bpy)(3)}(2+) type) and the electron-acceptor (A). 4-N- and 4-N-,4'-N-(2,4,6-triphenylpyridinio)-2,2'-bipyridine ligands (A(1)-bpy and A(2)-bpy, respectively) have been synthesized to give complexes with Ru(II), 1-bpy and 2-bpy, respectively. Combined solid-state analysis (X-ray crystallography), solution studies ((1)H NMR, cyclic voltammetry) and computational structural optimization allowed verifying that theta (1) angle approaches 90 degrees within 1-bpy and 2-bpy in solution. Also, anticipated existence of strong intercomponent electronic coupling has been confirmed by investigating electronic absorption properties and electrochemical behavior of the compounds. The capability of 1-bpy and 2-bpy to undergo PET process was evaluated by carrying out their photophysical study (steady state emission and time-resolved spectroscopy at both 293 and 77 K). The conformational dependence of photoinduced processes within P-(theta (1))-A systems has been established by comparing the photophysical properties of 1-bpy (and 2-bpy) with those of an affiliated species reported in the literature, 1-phen. A complementary theoretical analysis (DFT) of the change of spin density distribution within model [1-bpy(theta (1))](-) mono-reduced species as a function of theta (1) has been undertaken and the possibility of conformationally switching emission properties of P was derived.

show abstract

Preparation and NMR spectra of PF₄(N-N)⁺ and SiF₄(N-N), where N-N = 2,2′-bipyridine, 4-fluoro-2,2′-bipyridine, and 1,10-phenanthroline

Cited by 27 publications

References 4 publications

The boron trifluoride – base system: application of the coordination model of reaction mechanisms

The boron trifluoride – base system: application of the coordination model of reaction mechanisms

Photochemical and Thermal Reactions of Azido-oligopyridines: Diazepinones, a New Class of Metal-Complex Ligands

Photoinduced Processes within Compact Dyads Based on Triphenylpyridinium‐Functionalized Bipyridyl Complexes of Ruthenium(II)

Contact Info

Product

Resources

About