Characterization, Second-Harmonic Generation, and Gas-Sensitive Properties of Langmuir−Blodgett Films of 1,8-Naphthalimide-tri-tert-butylphthalocyanine

Abstract

Langmuir−Blodgett (LB) films of a new metal-free asymmetrically substituted phthalocyanine (Pc), 1,8-naphthalimide-tri-tert-butylphthalocyanine (NaBuPc), were fabricated and characterized by UV−vis spectrometry, atomic force microscopy, and small-angle X-ray diffraction (SAXRD). The results proved that the asymmetrically substituted Pc not only possesses good solubility in common organic solvents but also possesses an ideal LB film forming ability. From its surface pressure−area isotherm and SAXRD pattern, the configuration of the phthalocyanine molecules both at the air−water interface and in the LB films was demonstrated at a tilted angle (72°) to the water surface or solid substrate. The second-harmonic generation (SHG) of a three-layer LB film of NaBuPc was measured. Its SH intensity relative to a Y-cut quartz wedge is approximately 1.76. The values of second-order susceptibility (χ(2)) and the molecular hyperpolarizability (β) from the multilayers are 8.32 × 10-9 and 5.97 × 10-30 esu, respectively. Gas sensors based on the LB films of NaBuPc demonstrated good gas sensitivity to nitrogen dioxide at room temperature. A linear relationship between the logarithm of the concentration of NO2 and the resistance of the sensor was observed, providing a basis for the application as gas sensors in the future.

Characterisation of Langmuir–Blodgett films of new multinuclear copper and zinc phthalocyanines and their sensing properties to volatile organic vapours

“…2. A similar π-A isotherm has been observed for a 1,8-naphthalimide-tri-tert-butylphthalocyanine (NaBuPc) Langmuir monolayer at the water surface [25]. The surface pressure for our materials increased with decreasing surface area without an obvious phase transition up to 30 mN m −1 .…”

Monodisperse Polyelectrolyte‐Supported Asymmetric Lipid‐Bilayer Vesicles

“…Furthermore, the possibility to orient dipole moments of dye molecules embedded within asymmetric lipid bilayers potentially makes these systems interesting for nonlinear optical (including second-harmonic generation) studies. [36,37] Our current work is focused on the preparation of free-standing liposomes of asymmetric bilayers by employing decomposable PEs.…”

Synthesis of size controllable cu-phthalocyanine nanofibers by simple solvent diffusion method and their electrochemical properties

“…Phthalocyanines (Pcs) and their derivatives are excellent organic semiconductors and they have potential applications in chemical sensors [1][2][3], xerography [4], photoswitches [5], laser recording materials [6], photovoltaic cell [7,8] and field effect transistors [9,10]. Recently, one-dimensional structures of Pcs attract great interest, because they can offer larger surface areas compared to their films or bulk materials which can cause the enhanced optical and electronic properties.…”