Chiming Wang

Four Dibutylamino Substituents Are Better Than Eight in Modulating the Electronic Structure and Third-Order Nonlinear-Optical Properties of Phthalocyanines.

2(3),9(10),16(17),23(24)-Tetrakis(dibutylamino)phthalocyanine compounds M{Pc[N(C4H9)2]4} (1-5; M = 2H, Mg, Ni, Cu, Zn) were prepared and characterized by a range of spectroscopic methods in addition to elemental analysis. Electrochemical and electronic absorption spectroscopic studies revealed the more effective conjugation of the nitrogen lone pair of electrons in the dibutylamino side chains with the central phthalocyanine π system in M{Pc[N(C4H9)2]4} than in M{Pc[N(C4H9)2]8}, which, in turn, results in superior third-order nonlinear-optical (NLO) properties of H2{Pc[N(C4H9)2]4} (1) over H2{Pc[N(C4H9)2]8}, as revealed by the obviously larger effective imaginary third-order molecular hyperpolarizability (Im{χ((3))}) of 6.5 × 10(-11) esu for the former species than for the latter one with a value of 3.4 × 10(-11) esu. This is well rationalized on the basis of both structural and theoretical calculation results. The present result seems to represent the first effort toward directly connecting the peripheral functional substituents, electronic structures, and NLO functionality together for phthalocyanine molecular materials, which will be helpful for the development of functional phthalocyanine materials via molecular design and synthesis even through only tuning of the peripheral functional groups.

Novel bis(phthalocyaninato) rare earth complexes with the bulky and strong electron-donating dibutylamino groups: synthesis, spectroscopy, and SMM properties

Strong electron-donating dialkylamino groups were incoporated onto the phthalocyanine ligand in bis(phthalocyaninato) rare earth complexes for the first time to investigate their effects on the spectroscopic properties, electrochemistry, and electronic structure. The bis[2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyaninate] rare earth complexes M{Pc[N(C4H9)2]8}2 {Pc[N(C4H9)2]8 = 2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyanine, M = Y, Tb} (1, 2) were isolated from the condensation reaction of the corresponding metal free ligand in a refluxing mixture of n-octanol/1,2,4-trichrolobenzene (TCB) (1 : 5) in the presence of M(acac)3·nH2O (M = Y, Tb) in relatively good yields, with their sandwich double-decker nature revealed on the basis of their mass, 1H NMR, electronic absorption, IR, and EPR spectroscopic results in addition to elemental analysis. Their electrochemistry was investigated by cyclic voltammetry (CV). In particular, magnetic studies reveal the typical slow relaxation of the terbium double-decker, indicating its typical single-ion magnet (SIM) nature with a blocking temperature of 25 K and a spin reversal energy barrier of 752 ± 8 K, representing the sole example of sandwich-type tetrapyrrole lanthanide-based SMMs reported thus far with a blocking temperature over 20 K. Theoretical calculations disclose the effect of the bulky and strong electron-donating peripheral dialkylamino groups, which create a square-antiprismatic coordination geometry and intensified coordination field strength for the central terbium ion, resulting in the excellent magnetic performance of this terbium double-decker SIM.

A New Bis(phthalocyaninato) Terbium Single-Ion Magnet with an Overall Excellent Magnetic Performance

Bulky and strong electron-donating dibutylamino groups were incorporated onto the peripheral positions of one of the two phthalocyanine ligands in the bis(phthalocyaninato) terbium complex, resulting in the isolation of heteroleptic double-decker (Pc)Tb{Pc[N(C4H9)2]8} {Pc = phthalocyaninate; Pc[N(C4H9)2]8 = 2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyaninate} with the nature of an unsymmetrical molecular structure, a square-antiprismatic coordination geometry, an intensified coordination field strength, and the presence of organic radical-f interaction. As a total result of all these factors, this sandwich-type tetrapyrrole lanthanide single-ion magnet (SIM) exhibits an overall enhanced magnetic performance including a high blocking temperature (TB) of 30 K and large effective spin-reversal energy barrier of Ueff = 939 K, rendering it the best sandwich-type tetrapyrrole lanthanide SIM reported thus far.

Dysprosium Heteroleptic Corrole-Phthalocyanine Triple-Decker Complexes: Synthesis, Crystal Structure, and Electrochemical and Magnetic Properties

Two triple-decker dinuclear sandwich dysprosium complexes, which are represented as Dy2[Pc(OC5H11)8]2[Cor(FPh)3] (1) and Dy2[Pc(OC5H11)8]2[Cor(ClPh)3] (2), were synthesized and characterized by spectroscopic and electrochemical methods in nonaqueous media. Their electronic structures were also investigated on the basis of TD-DFT calculations. The sandwich triple-decker nature with the molecular conformation of [Pc(OC5H11)8]Dy[Cor(FPh)3]Dy[Pc(OC5H11)8] for compound 1 was unambiguously revealed by single-crystal X-ray diffraction analysis and showed each dyprosium ion to be octacoordinated by the isoindole and pyrrole nitrogen atoms of an outer phthalocyanine ring and the central corrole ring, respectively. In addition, the magnetic properties of both compounds have also been characterized for exploring the functionalities of these types of triple-decker complexes.

Phenanthro[4,5-fgh]quinoxaline-Fused Subphthalocyanines: Synthesis, Structure, and Spectroscopic Characterization.

A series of four phenanthro[4,5-fgh]quinoxaline-fused subphthalocyanine derivatives 0-3 containing zero, one, two, and three phenanthro[4,5-fgh]quinoxaline moieties, respectively, were isolated from the mixed cyclotrimerization reaction of 2,9-di-tert-butylphenanthro[4,5-fgh]quinoxaline-5,6-dicarbonitrile with 4,5-bis(2,6-diisopropylphenoxy)phthalonitrile and characterized by a series of spectroscopic methods including MALDI-TOF mass, (1) H NMR, electronic absorption, magnetic circular dichroism (MCD), and fluorescence spectroscopy. The molecular structures for the compounds 0 and 2 were clearly revealed on the basis of single-crystal X-ray diffraction analysis. Their electrochemical properties were also studied by cyclic voltammetry. In particular, theoretical calculations in combination with the electronic absorption and electrochemical analyses revealed the significant influence of the fused-phenanthro[4,5-fgh]quinoxaline units on the electronic structures.

Distribution of the unpaired electron in neutral bis(phthalocyaninato) yttrium double-deckers: An experimental and theoretical combinative investigation

The location of the unpaired electron in neutral bis(phthalocyaninato) yttrium double-decker complexes, with different substituents, has been studied on the basis of both experimental methods and density functional theory (DFT) calculations over the molecular structures, atomic charges, electronic absorption, infrared spectra, and electron paramagnetic resonance. The results reveal the location of the unpaired electron mainly on the carbon atoms of both tetrapyrrole chromophores with the population distribution obviously affected by the peripheral substituents.

Novel imine-linked porphyrin covalent organic frameworks with good adsorption removing properties of RhB

A new imine-linked porphyrin covalent organic framework (COF) CuP-DMNDA-COF with a large surface area was constructed from the condensation between 5,10,15,20-tetra(p-amino-phenyl)porphyrinatocopper(II) (CuTAPP) and 2,6-dimethoxynaphthalene-1,5-dicarbaldehyde (DMNDA) under solvothermal conditions. Simple treatment of CuP-DMNDA-COF with iron(III) in acetone led to the formation of the Fe-coordinated COF material CuP-DMNDA-COF/Fe, which exhibits superior adsorption performance for Rhodamine B (RhB) with easy recyclability and sustainability, indicating its good application potential for wastewater treatment.

Combinatorial experimental and DFT theoretical investigation over the formation mechanism of a binuclear phthalocyanine dimer

Herein, a density functional calculation method was used to explore the formation mechanism of a metal-free, homobinuclear phthalocyanine dimer. The result not only well rationalizes the Pc dimer formation starting from 1,2-diamino-9,10,16,17,23,24-hexa-(2,6-dimethylphenoxy)-tribenzotetrazaporphyrin (1-OR) through an intricate pathway but, more importantly, also predicts the formation of ammonia during the reaction process; this results in the successful experimental detection of NH4+ in the acidic reaction system. Further experimental efforts have facilitated the isolation of one of the theoretically revealed reaction intermediates di-[2-amino-7,8,14,15,21,22-hexa-(2,6-dimethylphenoxy)-tribenzotetrazaporphyrinato]-amine (9-OR); this indicates the significance of combining experimental with DFT calculation method towards clarifying the reaction mechanisms.

Novel, linear oligoisoindole compounds with a conjugated electronic structure

Unprecedented linear oligoisoindole derivatives including diisoindole, triisoindole, tetraisoindole, and hexaisoindole species, representing the new family rather than the traditional cyclic oligoisoindole ones, have been synthesized and spectroscopically characterized for the first time. Variable temperature NMR experiments in combination with DFT calculations reveal the tautomerization of the N–H protons between the outer and inner isoindole units in triisoindole, tetraisoindole, and hexaisoindole species at room temperature. The conjugated electronic structure nature of these oligoisoindole compounds has been clearly clarified on the basis of their single crystal molecular structure, electronic absorption, fluorescence, and electrochemical properties together with theoretical calculations. Moreover, the π Mayer bond order calculation suggests that these oligoisoindole compounds have two types of strong conjugated regions including the delocalized conjugated line across the whole skeleton and the localized conjugated circles at the benzene moieties, which are united together into a whole conjugated system by weak π linking bonds. In particular, the π bonds that pervade over all the linear conjugated oligoisoindole skeletons are comparable to those in the traditional cyclic oligoisoindole skeletons. This, in combination with the existence of the well-defined coordination moiety/moieties for these linear oligoisoindoles, suggests their promising application potential in diverse fields including sensors and electronic devices as their cyclic counterparts.