Photochemie von pentamethylcyclopentadienyl-substituierten Diphosphenen und Phosphaarsenen

Jutzi, Peter; Meyer, Udo

doi:10.1016/0022-328x(87)85161-6

Cited by 46 publications

(25 citation statements)

References 7 publications

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“…Due to dynamic rotationo ft he tBu groups in solution,a ll four Pa toms of the central P 4 scaffold become equivalent, resulting in apparent C 2h symmetry.T he chemicals hifts are similar to the NMR shifts of the P 3 unit of the structurallyr elated compounds 1 and 3, [14,17] but also comparable to either cyclotriphosphanes [21,30] or the bridgingP atoms in bicyclic tetraphosphanes. [22,[34][35][36] The experimental NMR data are in good agreement with calculated NMR shifts and coupling constants ( Table 2).…”

supporting

confidence: 81%

“…All PÀP bond lengths correspondt ot ypical single bonds (Sr cov = 2.22 ). [33] The angle between the least-squares planes of the three-a nd four-membered ring systems is 93.38,w hichc ompares to to those of other polycyclic phosphanes, such as bicyclic tetraphosphanes ( % 1008) [22,[34][35][36] or the aforementioned bicyclic hexaphosphanes 1 and 3 (89.88 and 99.28,r espectively). [14,17] In the solid-stateR amans pectrum, the P 6 scaffold can be identified by three characteristic bands at 414,4 42, and 537 cm À1 ,w hich were assigned on the basis of computed vibrational data ( Table 1, for more details see Figure S5 in the Supporting Information)…”

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confidence: 99%

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A Tricyclic Hexaphosphane

Bresien

Schulz

Villinger

2015

Chemistry A European J

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The reaction of the functionalized cyclo-tetraphosphane [ClP(μ-PMes*)]2 (Mes*=2,4,6-tri-tert-butylphenyl) with different Lewis bases led to the formation of an unprecedented tricyclic hexaphosphane, Mes*P6 Mes*. The formation of this compound was investigated by spectroscopic and theoretical methods, revealing an unusual ring expansion reaction. The title compound was fully characterized by experimental and computational methods.

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supporting

confidence: 81%

mentioning

confidence: 99%

A Tricyclic Hexaphosphane

Bresien

Schulz

Villinger

2015

Chemistry A European J

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“…In some cases, the formation of a labile cyclotetraphosphane arising from the head-to-head dimerization of cis -diphosphenes is experimentally observed 66, 74, 75 or implied by the products formed 69, 73, 76. In other photochemical experiments, evidence for a transient cyclotetraphosphane is sought but not found 70, 72.…”

Section: Resultsmentioning

confidence: 99%

Twisting the Phenyls in Aryl Diphosphenes (Ar−P═P−Ar). Significant Impact upon Lowest Energy Excited States

et al. 2009

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Aryl diphosphenes (Ar-P=P-Ar) possess features that may make them useful in photonic devices, including the possibility for photochemical E-Z isomerization. Development of good models guided by computations is hampered by poor correspondence between predicted and experimental UV/vis absorption spectra. An hypothesis that the phenyl twist angle (i.e. PPCC torsion) accounts for this discrepancy is explored, with positive findings. DFT and TDDFT (B3LYP) were applied to the phenyl-P=P-phenyl (Ph-P=P-Ph) model compound over a range of phenyl twist angles, and to the Ph-P=P-Ph cores of two crystallographically characterized diphosphenes: bis-(2,4,6-tBu 3 C 6 H 2 )-diphosphene (Mes*-P=P-Mes*) and bis-(2,6-Mes 2 C 6 H 3 )-diphosphene (Dmp-P=P-Dmp). A shallow PES is observed: the full range of phenyl twist angles is accessible for under 5 kcal/mol. The KohnSham orbitals (KS-MOs) exhibit stabilization and mixing of the two highest energy frontier orbitals -the n + and π localized primarily on the -P=P-unit. A simple, single-configuration model based upon this symmetry-breaking is shown to be consistent with the major features of the measured UV/ vis spectra of several diphosphenes. Detailed evaluation of singlet excitations, transition energies and oscillator strengths with TDDFT showed that the lowest energy transition (S 1 ← S 0 ) does not always correspond to the LUMO ← HOMO configuration. Coupling between the phenyl rings and central -P=P-destabilizes the π-π* dominated state. Hence, the S 1 is always n + -π* in nature, even with a π-type HOMO. This coupling of the ring and -P=P-π systems engenders complexity in the UV/vis absorption region, and may be the origin of the variety of photobehaviours observed in diphosphenes.

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“…dazu (C5MeS)P = P(C5Me5)'): P-C = 188. (6). Es fallt besonders auf, daB der Abstand zwischen den Bruckenkopf-Phosphor-Atomen in 3 (219.6 pm) deutlich langer ist als derjenige in 5 (212.9 pm) und 6 (216.6 pm); Fur die relativ kurze P-P-Bindung in 5 ist ein deutlicher Doppelbindungsanteil diskutiert worden Im Cyclopolyphosphan 3 unterscheiden sich alle P -P-Bindungen innerhalb des Bicyclobutan-Geriistes nur geringfugig.…”

Section: Kristallstrukturen Von 2 Undunclassified

Synthese und Struktur der Polycyclohexaphosphane P₆(C₅Me₅)₄ und P₆(C₅Me₅)₂

et al. 1991

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Synthesis and Structure of the Polycyclohexaphosphines P6(C5Me5)4 and P6(C5Me5)2The cyclotriphosphine (PC5Me5)3 (1) decomposes in boiling benzene to give the bicyclo[3.1.O]hexaphosphine P6(C5Me5)4 (2) which yields the tricycl0[3.1.0.0~.~ lhexaphosphine P6(C&k5)2 (3) in boiling xylene. The structures of 2 and 3 have been determined by 31P-, 13C-, and 'H-NMR spectroscopy and by X-ray crystallography. 3 represents the first member of a new class of polyphosphines. The specific thermolysis of 1 and 2 under comparatively mild conditions is based on the easy homolytic cleavage of P -C5Me5 bonds in these compounds.Der o-gebundene Pentamethylcyclopentadienyl-Ligand (C5Me5) vereinigt in sich mehrere bemerkenswerte Eigenschaften I). So ermoglicht seine Sperrigkeit die Stabilisierung reaktiver Molekiile. Des weiteren sind Bindungen zu diesem Liganden oftmals vergleichsweise schwach. Das auI3ert sich in der Dynamik entsprechender Verbindungen (sigmatrope Umlagerungen) und hat zur Folge, daI3 Element -C5Me5-Bindungen eine Funktionalitat gegeben ist, die zu verschiedenartigen Reaktionen genutzt werden kann.In unserer Arbeitsgruppe haben wir unter anderem auch C5MeS-substituierte Phosphor-Verbindungen naher untersucht. So gelang uns aufgrund der Sperrigkeit des C5MeS-Liganden die kinetische Stabilisierung von Phosphor -Phosphor-(p -p)x-Doppelbindungen im zweifach C,Me,-substituierten Diphosphen (CSMe5)P = P(CSMe5)') sowie im gemischt substituierten Diphosphen (CSMeS)P = PMes* 3, [Mes* = 2,4,6-Tri(tert-butyl)phenyl, Supermesityl]. Die Funktionalitat des CsMeS-Liganden in diesen Verbindungen konnte durch verschiedenartige Experimente belegt werden. So sind Substitutionsreaktionen moglich, die unter Erhaltung der P = P-Bindung ablaufen*); ausgehend vom Diphosphen (C,Me,)-P = PMes* und vom Lithiumsupermesitylphosphid Mes*PHLi gelang die Synthese von Triphosphaallyllithium [Mes* -P -P -PMes*lo LiQ ' ). Bei der Reaktion von (C5Me5)P = PMes* mit Cr(C0)3(CH3CN)3 erfolgt einc Wanderung des C5MeS-Liganden an das Ubergangsmetall-Atom; nach Verlust der Acetonitril-Liganden entsteht der Diphosphenyl-Komplex (CsMes)(C0)3Cr-P = PMes* ". Photoreaktionen der Diphosphene (C5Mes)P = P(C,Me5) und (C5Mes)P = PMes* fiihren nach Verlust von C5Me5-Liganden zu den Verbindungen P4(CSMe5)* und P4 bzw. P4Mes** und Ma*-P=PMes*6). (111, das aus n-Hexan als gelbe Nadeln isoliert werden kann.

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Photochemie von pentamethylcyclopentadienyl-substituierten Diphosphenen und Phosphaarsenen

Cited by 46 publications

References 7 publications

A Tricyclic Hexaphosphane

A Tricyclic Hexaphosphane

Twisting the Phenyls in Aryl Diphosphenes (Ar−P═P−Ar). Significant Impact upon Lowest Energy Excited States

Synthese und Struktur der Polycyclohexaphosphane P₆(C₅Me₅)₄ und P₆(C₅Me₅)₂

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Photochemie von pentamethylcyclopentadienyl-substituierten Diphosphenen und Phosphaarsenen

Cited by 46 publications

References 7 publications

A Tricyclic Hexaphosphane

A Tricyclic Hexaphosphane

Twisting the Phenyls in Aryl Diphosphenes (Ar−P═P−Ar). Significant Impact upon Lowest Energy Excited States

Synthese und Struktur der Polycyclohexaphosphane P6(C5Me5)4 und P6(C5Me5)2

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Synthese und Struktur der Polycyclohexaphosphane P₆(C₅Me₅)₄ und P₆(C₅Me₅)₂