The chemistry of cymantrene

Abstract

also for other schemes. In our calculation the transfer functions of the spectrometer and the detector are not considered, because usually the contributions to the lineshape and intensity of these parts can be safely neglected or are easily taken into account. Our results can be applied to uniaxial crystals and also to orthorhombic crystals as long as the scattering plane coincides with a plane of symmetry of the indicatrix. In the last part of the paper the calculated results are compared with experimental results from trigonal KBr03, where significant changes of width, height and asymmetry of the polariton lines have been observed. 2 The experimental arrangement The set up of Claus (1971), shown in figure 1 in a horizontal projection, allows a precise control of the mean scattering Abstract The instrumental lineshapes of polaritons observed in near forward scattering experiments with the arrangement suggested by Claus have been calculated by means of geometrical optics. The width of the exciting laser beam, the finite apertures of blinds and the acceptance angles of lenses have been considered. The results are compared with experimental lineshapes of a phonon polariton in uniaxial potassium bromate.

The reaction of 2,5-diphenylphosphacymantrene with solid KOH in the presence of crown ethers: Synthesis of the anionic η4-phosphoryl manganese complexes

“…[1]). Replacement of one CH group in the ligand for a heteroatom changes the property of a compound greatly.…”

Synthesis and Spectroscopic Studies of the Photochromism of Bifunctional Derivatives of Cymantrene in Solution and without Solvent

“…Ligand exchange at the metal atom is a fundamental property of transition-metal half-sandwich complexes and is applied widely as the basis for the synthesis of various compounds. [1][2][3][4][5][6][7] In particular, the photoinduced ligand exchange of some functional derivatives of cymantrene [(cyclopentadienyl)tricarbonylmanganese], (benzene)tricarbonylchromium, and related π-complexes is often accompanied by a substantial color change of the solution and the formation of photochromic systems. [8][9][10][11][12][13][14][15][16][17] Traditionally, photoinduced ligand exchange for cymantrene derivatives is performed by irradiation of solutions in alkanes, benzene, tetrahydrofuran (THF), or acetonitrile.…”

Synthesis of a 2-benzocymantrenylpyridine and further mechanistic insights

“…From a practical point of view the synthesis of substituted cymantrenes and other benzo and dibenzo analogues remains a challenge [8,9]. The difficulties associated with the syntheses of cymantrenes, as well as with their indenyl and fluorenyl analogues, have hampered their broad use in catalysis as potential planar chiral ligands [10,11].…”

“…The second is the thermolytic reaction of diazocyclopentadienes with alkyl and aryl-manganesecarbonyl compounds, which entails the transient formation of carbene or carbenoid e type intermediates [12e15]. The third method consists of the thermolysis of cyclopentadienes with Mn 2 (CO) 10 [8]. In the present study we disclose our results on the use of 2-indenylpyridine, as a substrate for the synthesis of a prototypical planar chiral cymantrene analogue, i.e 2-benzocymantrenylpyridine, i.e.…”

“…Three main routes to functionalized cymantrene derivatives from cyclopentadienyl-type ligands can be considered. The first is the reaction of cyclopentadienylides with (CO) 5 MnX (X ¼ halide) compounds that leads, via a multistep process, to a thermodynamically stable pentahapto cyclopentadienyl complex [8]. The second is the thermolytic reaction of diazocyclopentadienes with alkyl and aryl-manganesecarbonyl compounds, which entails the transient formation of carbene or carbenoid e type intermediates [12e15].…”