185692-94-8Relevant academic research and scientific papers
Observation of quantum paraelectricity in an intermolecular ionic hydrogen-bonded crystal of a squaric acid derivative
Takasu, Isao,Izuoka, Akira,Sugawara, Tadashi,Mochida, Tomoyuki
, p. 5527 - 5531 (2004)
Proton transfer in a hydrated crystal of a squaric acid derivative, p-phenylenebis(squaric acid) (PBSQ), was investigated by means of ac dielectric measurements. The crystal consisted of PBSQ monoanions and protonated water dimer (H5O2+) counter cations, and a highly symmetric, one-dimensional hydrogen-bonded chain was formed through strong OH?O- ionic hydrogen bonding between deprotonated PBSQ moieties. The permittivity of the hydrated crystal was nearly temperature independent (ε′ ～ 9), but the deuterated crystal exhibited a Curie-Weiss type temperature dependence and underwent depression of the permittivity at 28 K, which is the characteristic of an (anti)ferroelectric phase transition. Thus, we conclude that the dielectric response of the hydrated PBSQ crystal originates from proton transfer along the intermolecular hydrogen bond and that the temperature-independent dielectric behavior can be interpreted in terms of quantum paraelectricity.
Synthesis and light absorption/emission properties of novel bis-squaraine dyes with extensively conjugated π-electron systems
Yagi, Shigeyuki,Murayama, Shin,Hyodo, Yutaka,Fujie, Yoshihiko,Hirose, Msahiko,Nakazumi, Hiroyuki
, p. 1417 - 1419 (2007/10/03)
Novel symmetrical bis-squaraine dyes have been synthesised, in which two squaryl moieties are conjugatively linked by a phenylene or biphenyl unit. Such linkages produce significant perturbation of the absorption and fluorescence spectra in comparison wit
