Hexaethinylbenzol

Diercks, Rainer; Armstrong, James C.; Boese, Roland; Vollhardt, C.

doi:10.1002/ange.19860980319

Cited by 94 publications

(42 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This vibration pattern can be observed for all other angular annelated [N]phenylenes. The fixed point moves towards the interior benzene moiety for (2), (3) and (4). The value of a is increased from 120 to 129 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Shpol'skii spectroscopy and vibrational analysis of [N]phenylenes

Dosche

Kumke

Ariese

et al. 2003

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Shpol'skii spectroscopy and vibrational analysis of [N]phenylenes U n i v e r s i t ä t P o t s d a mVibrationally resolved fluorescence spectra of four angular [N]phenylenes were recorded with laser excited Shpol 'skii spectroscopy (LESS) in an n-octane matrix at 10 K. In general, the same vibrational frequencies were observed in the fluorescence excitation and emission spectra, indicating that the geometries of ground and electronically excited state are very similar. Because of intensity borrowing from the S 2 state, vibrations of two different symmetries were observed in the fluorescence excitation spectra of angular [3]phenylene and zig-zag [5]phenylene. This finding allowed the location of the S 2 state for these compounds. DFT calculations (RB3LYP/6-31G*) of the ground state vibrational frequencies were made. The calculated vibrational modes were in reasonably good agreement with the experimental data. A new very low-frequency vibration of approximately 100 cm À1 was predicted and experimentally confirmed for all [N]phenylenes investigated. This vibration seems to be unique for [N]phenylenes and is attributed to an in-plane movement of the carbon backbone.

show abstract

Section: Discussionmentioning

confidence: 99%

“…In particular, in the site-selective excitation spectrum of zig-zag [4]phenylene in the range between 150 cm À1 < Dn < 500 cm …”

Section: Zig-zag [4]phenylene (3)mentioning

confidence: 99%

Shpol'skii spectroscopy and vibrational analysis of [N]phenylenes

Dosche

Kumke

Ariese

et al. 2003

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…The resulting residue was dissolved in Et 2 O and adsorbed on alumina (activity III). Column chromatography (pentane) with alumina (III) gave 5 [30] (0.303 g, 0.462 mmol) and [18]crown-6 (0.063 g, 0.237 mmol) in DME (50 mL). The mixture was stirred for 30 min, decanted from solids, and subsequently degassed with N 2 .…”

Section: 3-bis(trimethylsilyl) Linear [3]phenylene (5 B)mentioning

confidence: 99%

On the Nature of Nonplanarity in the [N]Phenylenes

et al. 1999

View full text Add to dashboard Cite

The [N]phenylenes display marked deformation from planarity in the crystalline state. In order to probe the generality of this phenomenon, several derivatives were synthesized and their single-crystal X-ray structures were obtained. All new compounds displayed some degree of nonplanarity. Thus, for example, the parent triangular [4]phenylene (4 b) has a median bend angle at the ring junction of 1.58 and a range of 0.38 to 3.58, whereas hexakis[triisopropylsilyl(ethynyl)] triangular [4]phenylene (4 c) possesses the bulkiest appendages and the largest median bend angle and range (3.88 and 1.78 ± 5.68, respectively). A detailed analysis of the bending and twisting angles at the ring junctions, however, revealed that the magnitude of deformations were independent of topology, molecular size, and substituent type. In contrast to the phenylenes, a Cambridge Structural Database (CSD) search of unsubstituted and non-peri-substituted naphthalenes and anthracenes shows these molecules to be virtually planar in the solid state. A comparison of the single-point energies (HF/6-31G*) of the phenylenes with the acenes calculated for molecules possessing a fixed bend angle at the ring fusion of 38, 68, 98, and 128 reveals the former to be 26 % to 45 % easier to deform than the latter. Based on these results, the nonplanarity seen for the phenylenes is most likely a consequence of crystalpacking forces deforming particularly flexible molecules.

show abstract

“…[15] The bond lengths and bond angles for 7 are in excellent agreement with the expected values. [1,5,7] Figure 3 shows the packing of 7 in the solid state. The molecules are arranged in tilted stacks that are 0.97-nm apart along the b axis in a classic herringbone arrangement.…”

mentioning

confidence: 97%

“…[1] Since then, peralkynylated cyclobutadiene complexes, cymantrenes, ferrocenes, cylcopentadienyl radicals, thiophenes, and extended systems derived from tetraethynylethylenes and hexaethynylbenzenes have been reported. [2][3][4][5][6][7] Peralkynylated N-heterocycles are scarce, and only recently peralkynylpyrazinophorphyrazine and triethynyltriazine were reported.…”

mentioning

confidence: 99%