Controllable Growth of Well-Defined Regular Multiporphyrin Array Nanocrystals at the Water−Chloroform Interface

Abstract

On the basis of the coordination geometry of metal ions, regular cubic, clubbed, and wirelike nanocrystals of Cd(2+)-/PtCl(6)(2-)-mediated, and Hg(2+)-/Ag(+)-/PtCl(4)(2-)-mediated multiporphyrin arrays have been grown at the water-chloroform interface. The nanocrystal growth process was monitored by the transmission electron microscopy (TEM), which revealed (1) an intrinsic rule for coordination polymers, that is, the geometries of metal ions (as connects for the coordination polymers) dominate the frameworks of the related polymeric nanocrystals, and (2) one kind of intuitive nanocrystal growth processes at the interfaces. Both electron diffraction and X-ray diffraction patterns indicated the formation of well-defined nanocrystals. It was found that single-/microcrystals were formed at first, and then they grew into polycrystals. The nanocrystal layer was transferred onto Si and quartz substrate surfaces by the Langmuir-Blodgett method, with its composition analyzed by X-ray photoelectron spectroscopy as well as the arrangement of porphyrin macrocycles in the nanocrystals by UV-vis absorption spectroscopy.

Porous Porphyrin Nanoarchitectures on Surfaces

“…[46][47][48][49][50][51][52][53][54][55][56][57][58][59] Qian et al employed a metal salt aqueous solution as a subphase and porphyrin molecules as the spreading substance. [54][55][56][57][58][59] The combination of functionalized porphyrin molecules such as 5,10,15,20-tetrakis(4-pyridyl)-21H,23H-porphyrin (H 2 TPyP) and its metal ion derivatives (MTPyP, M = Zn II , Mn III , TiO) with palladium salts was expected to lead to the formation of metal-mediated porphyrin arrays. [54][55][56][57] The specific combination of molecular building blocks was Eur.…”

“…The same group also used H 2 TPyP molecules with different assembly-mediating metal ions (Cd 2+ , PtCl 6 2-/ PtCl 4 2-, Ag + , and Hg 2+ ). [58][59] It should be noted that, in this case, the metal ion aqueous solution was added onto the H 2 TPyP chloroform solution. In this procedure, the order of the layers is inverted relative to that in the general LB fabrication method.…”

Challenges and breakthroughs in recent research on self-assembly

“…Advanced functions such as electroactive properties [745,746], photo-induced electron transfer [747], logic gate [748], photo-switched wettability control [749], protonation-induced rearrangement [750], and vectorial electron transfer [751] were reported as well as more fundamental science related to phase boundary [752], domain formation [753], acid-base dissociation [754,755], elasticity [756], basic characterization [757][758][759]. Furthermore, other interfaces such as the air-mercury interface [760] and interfaces between water and organic solvents [761][762][763][764] have been used for self-assembly processes.…”

Effect of Transition Metal Cations on Assembly of Highly Ordered 2D Multiporphyrin Arrays on Liquid and Solid Substrates

“…В монослое TPyP на поверхности чистой воды структура электронного спектра соответствует хорошо известной структуре спектра раствора лиганда. Интенсивная полоса Соре при 440 нм (электронный переход В(0,0)) дополняется областью Q-полос Q y (0,1) при 518 нм и Q y (0,0) при 552 нм, а также Q x (0,1) при 592 нм и Q x (0,0) при 646 нм, при этом полоса Соре смещается относительно раствора в хлороформе батох-ромно на 23 нм, что хорошо согласуется с имеющимися данными [34][35] и свидетельствует об агрегации молекул в монослое на поверхности воды с образованием пла-нарных агрегатов J-типа. Принципиальные изменения происходят в электронных спектрах поглощения (ЭСП) монослоев TPyP при введении в субфазу катионов.…”