Chemistry of indole

Quadratic Optical Nonlinearities of N‐Methyl and N‐Aryl Pyridinium Salts

“…1). Hence, the two-state approximation would be expected to afford more reliable estimates of b 0 for [9]PF 6 and [10]PF 6 , and the data obtained are consistent with substantial underestimation of b 0 for [11]PF 6 and [12]PF 6 . In contrast, when using a 800 nm fundamental, all four compounds show similar levels of absorption at both 800 and 400 nm.…”

“…The compounds N-methyl-4-picolinium iodide [25] ([mepic + ]I), 4-(dimethylaminophenyl)pyridine´0.15H 2 O, [11] 4-(4-dimethylaminophenyl)-N-methylpyridinium iodide [12] ([1]I), 4-(4-dimethylaminophenyl)-N-phenylpyridinium chloride [12] ([2]Cl), 4-(4-dimethylaminophenyl)-N-(2,4-dinitrophenyl)pyridinium chloride´0.8H 2 O [12] ([3]Cl´0.8H 2 O), trans-4¢-(dimethylamino)-N-methyl-4-stilbazolium hexafluorophosphate [7] ([5]PF 6 ), trans-4¢-(dimethylamino)-N-phenyl-4-stilbazolium hexafluorophosphate [7] ([6]PF 6 ), trans-4¢-(dimethylamino)-N-(2,4-dinitrophenyl)-4-stilbazolium hexafluorophosphate [7] ([7]PF 6 ), trans-4¢-(dimethylamino)-N-(2-pyrimidyl)-4-stilbazolium hexafluorophosphate [7] ([8]PF 6 ), trans-4¢-methoxy-N-methyl-4-stilbazolium iodide [26] ([13]I), N-phenyl-4-picolinium chloride´1.25H 2 O [7] ([ppic + ]Cl´1.25H 2 O), trans-4¢-methoxy-4-stilbazole [27] and 4-picolyltriphenylphosphonium chloride [28] were prepared according to published procedures. [ and 2-chloropyrimidine (573 mg, 5.00 mmol) was heated quickly to 80 C, forming a red melt.…”

“…An important factor here is evidently the complicating effects of resonance when HRS measurements are carried out close to ICT absorption bands. For example, considering the 1300 nm HRS studies on the series [9±12]PF 6 ; [9]PF 6 , and [10]PF 6 show relatively small absorptions at the second harmonic wavelength of 650 nm, whilst [11]PF 6 and [12]PF 6 absorb very strongly (Fig. 1).…”

“…Furthermore, crystalline salts The N-(2-pyrimidyl) (2-Pym) cations in [4]PF 6 , [12]PF 6 , and [16]PF 6 were synthesized by S N Ar reactions of the appropriate pyridyl derivative with 2-chloropyrimidine, in the presence of silver trifluoroacetate. The N-(2,4-dinitrophenyl) (2, cations in [11]PF 6 and [15]PF 6 were synthesized similarly by S N Ar reactions with 2,4-dinitrochlorobenzene. Further reactions of [11]Cl and [15]Cl with aniline afforded the N-phenyl cations in [10]PF 6 and [14]PF 6 .…”

“…The N-(2,4-dinitrophenyl) (2, cations in [11]PF 6 and [15]PF 6 were synthesized similarly by S N Ar reactions with 2,4-dinitrochlorobenzene. Further reactions of [11]Cl and [15]Cl with aniline afforded the N-phenyl cations in [10]PF 6 and [14]PF 6 . The precursor to [10±12]PF 6 , trans-4-(4-dimethylaminophenyl-4-buta-1,3-dienyl)pyridine, was synthesized via standard Wittig±Horner chemistry.…”