A molecular mechanics approach to mapping the conformational space of diaryl and triarylphosphines

Fey, Natalie; Howell, James A. S.; Lovatt, Jonathan D.; Yates, Paul C.; Cunningham, Desmond; McArdle, Patrick; Gottlieb, Hugo E.; Coles, Simon J.

doi:10.1039/b610123b

Cited by 21 publications

(14 citation statements)

References 43 publications

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“…39 It has been found that tris-ortho-tolyl phosphine adopts only two (exo 2 and exo 3 ) out of the four possible conformations (exo 0 , exo 1 , exo 2 and exo 3 ) in crystal structures. [39][40][41][42] Baber et al have noted that the exo 3 conformation is preferred in metal complexes with low steric demand (two and three coordinate complexes, and some tetrahedral systems), while square planar or octahedral complexes feature ligands with an exo 2 conformation. 42 The (EF) 6 embrace is hindered and not possible when the exo 2 conformation is adopted, therefore the extra stability that the (EF) 6 embrace imparts on the crystal packing is likely to favour the exo 3 conformation over the exo 2 whenever sterically possible.…”

Section: Structural Relationships Between Tolyl-substituted R 3 Ei 2 ...mentioning

confidence: 99%

Structural relationships between o-, m- and p-tolyl substituted R3EI2 (E = As, P) and [(R3E)AuX] (E = As, P; X = Cl, Br, I)

et al. 2010

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The compounds R 3 EI 2 (R ¼ o-tolyl, E ¼ As, 1a; R ¼ m-tolyl, E ¼ P 1c; R ¼ p-tolyl, E ¼ As, 1d, P, 1e), which display the charge transfer spoke structure, and [(o-tolyl 3 As)AuCl] 2 have been synthesised and their solid state structures compared to the related complexes, Va; Br, VI; I, VII) on the basis of a similarity of their molecular shape and volume. All of the new compounds 1a, 1c-1e and 2 have been fully spectroscopically characterised and by single crystal X-ray crystallography. The sterically demanding exo 3 o-tolyl ring conformation is observed for 1a, which is comparable to that reported for o-tolyl 3 PI 2 1b, with a long As-I bond 2.7351( 14)A and short I/I distance 2.9528(11) A. The exo 3 o-tolyl ring conformation is maintained on complexation to gold(I) in 2, but has no significant impact on the expected bond lengths, with As-Au 2.3443(15)A and Au-Cl 2.284(4) A. The exo 3 conformation appears to be stabilised in both cases by the formation of a six-fold edge-to-face (EF) 6 embrace. It is found that in some cases the structures of the dihalogen adducts and the gold(I) complexes are isomorphous indicating that ligand packing requirements are most significant i.e. for 1c and IV. Where the structures digress this is due either to the greater ability of the dihalogen adduct to engage in hydrogen bonding 1a, b and I-III; or subtle changes in the nature of the tolyl ring embraces 1d, e and V-VII. Subtle changes in the nature of the tolyl ring embraces also account for the different polymorphs I and Ia and V and Va. There is no credible evidence to suggest that the aurophilic contact, seen in only one polymorph Va, exerts any influence on the overall crystal packing. The structural comparisons presented here add further to the applicability of the recently recognised structural mimicking ability of the R 3 PX 2 systems and [R 3 PAuX] complexes, and that the aurophilic contact is a poor supramolecular synthon.

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Section: Structural Relationships Between Tolyl-substituted R 3 Ei 2 ...mentioning

confidence: 99%

Structural relationships between o-, m- and p-tolyl substituted R3EI2 (E = As, P) and [(R3E)AuX] (E = As, P; X = Cl, Br, I)

et al. 2010

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“…The parent imidazole compound, 2-(2 0 -tert-butylphenyl)-4,5-diphenylimidazole, 1, (Scheme 1) was synthesised using a 3 step procedure consisting of modifications of known methods. This briefly comprised the conversion of 2-tert-butylaniline to 2-tert-butyliodobenzene 19 via the diazonium salt, lithium-halogen exchange with n-BuLi and quenching with N,N-dimethylformamide to produce 2-tert-butylbenzaldehyde. 20 This was followed by a condensation reaction with benzil and ammonium acetate in acetic acid to form the imidazole ring under microwave irradiation.…”

Section: Resultsmentioning

confidence: 99%

The formation of peroxide degradation products of photochromic triphenylimidazolyl radical-dimers

Edkins

Probert

Fucke

et al. 2013

Phys. Chem. Chem. Phys.

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Following the recent report of Abe and co-workers (Phys. Chem. Chem. Phys., 2012, 14, 5855) of the isolation of a bridging peroxide of a naphthalene-tethered bisimidazolyl diradical, it is reported herein that this degradation pathway is a more general phenomenon for the chromic dimers of 2,4,5-triphenylimidazolyl radical (TPIR) materials, with non-tethered TPIRs forming similar oxygen adducts. The peroxides of two derivatives have been characterised by single crystal X-ray diffraction (SC-XRD) and it is identified that the 4-position of the imidazolyl ring is the site susceptible to reaction with oxygen. Furthermore, mass spectrometry has been used to show that for a range of five known, non-tethered derivatives, peroxide formation can be detected within 30 minutes when samples are irradiated under an oxygen atmosphere, thus presenting a significant challenge to the long term use of this class of material in colour-switching device applications.

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“…The synthesis starts with aryl bromides 1 and 2 , prepared from the corresponding commercially available aniline derivatives using a Sandmeyer reaction 30 (Scheme ). The addition of magnesium metal to the aryl bromide ( 1 or 2 ) in tetrahydrofuran (THF) generates the respective Grignard reagents, which are then treated with ClP(NEt 2 ) 2 31.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC₆H₄PH₂ and 2‐RC₆H₄P(SiMe₃)₂ (R = 2‐i‐Pr‐ or 2‐t‐Bu‐)

Dugal-Tessier¹,

Kuhn²,

Dake³

et al. 2010

Heteroatom Chemistry

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A molecular mechanics approach to mapping the conformational space of diaryl and triarylphosphines

Abstract: A molecular mechanics force field has been developed which accurately reproduces experimental solid state structures and conformer interconversion barriers for a series of sterically congested diaryl and triaryl phosphines and some of their chalcogenide and Cr(CO)5 derivatives.

Cited by 21 publications

References 43 publications

Structural relationships between o-, m- and p-tolyl substituted R3EI2 (E = As, P) and [(R3E)AuX] (E = As, P; X = Cl, Br, I)

Structural relationships between o-, m- and p-tolyl substituted R3EI2 (E = As, P) and [(R3E)AuX] (E = As, P; X = Cl, Br, I)

The formation of peroxide degradation products of photochromic triphenylimidazolyl radical-dimers

Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC₆H₄PH₂ and 2‐RC₆H₄P(SiMe₃)₂ (R = 2‐i‐Pr‐ or 2‐t‐Bu‐)

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A molecular mechanics approach to mapping the conformational space of diaryl and triarylphosphines

Abstract: A molecular mechanics force field has been developed which accurately reproduces experimental solid state structures and conformer interconversion barriers for a series of sterically congested diaryl and triaryl phosphines and some of their chalcogenide and Cr(CO)5 derivatives.

Cited by 21 publications

References 43 publications

Structural relationships between o-, m- and p-tolyl substituted R3EI2 (E = As, P) and [(R3E)AuX] (E = As, P; X = Cl, Br, I)

Structural relationships between o-, m- and p-tolyl substituted R3EI2 (E = As, P) and [(R3E)AuX] (E = As, P; X = Cl, Br, I)

The formation of peroxide degradation products of photochromic triphenylimidazolyl radical-dimers

Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC6H4PH2 and 2‐RC6H4P(SiMe3)2 (R = 2‐i‐Pr‐ or 2‐t‐Bu‐)

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Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC₆H₄PH₂ and 2‐RC₆H₄P(SiMe₃)₂ (R = 2‐i‐Pr‐ or 2‐t‐Bu‐)