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} (<b>1</b>–<b>5</b>; 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} (<b>1</b>) 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

Self-Assembled Zn(II) Coordination Complexes Based on Mixed V‑Shaped Asymmetric Multicarboxylate and N‑Donor Ligands

Hydrothermal reaction between Zn­(OAc)₂·2H₂O and three asymmetric semirigid V-shaped multicarboxylate ligands H₃L^1–3 with the help of a 4,4'-bipyridine (4,4'-bpy) or 1,4-bis­(imidazol-1-ylmethyl)­benzene (bix) linker led to the isolation of six new coordination polymers, including [Zn₃(L¹)₂(4,4′-bpy)₂]_<i>n</i>·(H₂O)_2<i>n</i> (<b>1</b>), [Zn₃(L²)₂­(4,4′-bpy)­(H₂O)₂]_<i>n</i>·(H₂O)_2<i>n</i> (<b>2</b>), [Zn₃(L³)₂­(4,4′-bpy)₂­(H₂O)₄]_<i>n</i>·(H₂O)_6<i>n</i> (<b>3</b>), [Zn₃(L¹)₂­(bix)₃]_<i>n</i>·(H₂O)_7<i>n</i> (<b>4</b>), [Zn₃(L²)₂­(bix)₃]_<i>n</i>·(H₂O)_4<i>n</i> (<b>5</b>), and [Zn₃(HL³)₂­(bix)₂]_<i>n</i> (<b>6</b>), where H₃L¹, H₃L², H₃L³ ligands represent 3-(2-carboxyphenoxy)­phthalic acid, 4-(2-carboxyphenoxy)­phthalic acid, 3-(4-carboxyphenoxy)­phthalic acid, respectively. Single crystal X-ray diffraction analysis reveals a three-dimensional (3D) network for <b>1</b> and <b>3</b>–<b>5</b> but a two-dimensional (2D) structure for <b>2</b> and <b>6</b>. Despite the construction from the polymetallic chains connected by the 4,4′-bpy ligands for both compounds <b>1</b> and <b>2</b>, a 3D architecture was revealed for the former species while a 2D configuration for the latter one. Complex <b>3</b> contains open nanotube building units composed of sole 44-numbered metallomacrocycles. For <b>4</b>, the 20-numbered metallomacrocycle subunits linked by Zn ions give a 1D chain, which further form a 3D polymeric structure with the help of the other cyclic-shaped subunits made from the bix ligands and Zn ions. A 3D framework of <b>5</b> is generated from the 2D sheets simplified as a (6,3) net bound by the bix ligands. Compound <b>6</b> shows a 2D corrugated framework simplified as a (4,4) net assembled by the bix ligand and dinuclear zinc unit as node. These results seem to suggest that the diversity in the building subunits formed in <b>1</b>–<b>6</b> actually originates from the intrinsic nature of the three asymmetric V-shaped tricarboxylate ligands together with the tunable coordination geometry and molecular configurations of ligands by the N-donor ligand employed. In addition, the thermal stability and luminescence properties for the series of six complexes have also been investigated

Self-Assembled Zn(II) Coordination Complexes Based on Mixed V‑Shaped Asymmetric Multicarboxylate and N‑Donor Ligands

Hydrothermal reaction between Zn­(OAc)₂·2H₂O and three asymmetric semirigid V-shaped multicarboxylate ligands H₃L^1–3 with the help of a 4,4'-bipyridine (4,4'-bpy) or 1,4-bis­(imidazol-1-ylmethyl)­benzene (bix) linker led to the isolation of six new coordination polymers, including [Zn₃(L¹)₂(4,4′-bpy)₂]_<i>n</i>·(H₂O)_2<i>n</i> (<b>1</b>), [Zn₃(L²)₂­(4,4′-bpy)­(H₂O)₂]_<i>n</i>·(H₂O)_2<i>n</i> (<b>2</b>), [Zn₃(L³)₂­(4,4′-bpy)₂­(H₂O)₄]_<i>n</i>·(H₂O)_6<i>n</i> (<b>3</b>), [Zn₃(L¹)₂­(bix)₃]_<i>n</i>·(H₂O)_7<i>n</i> (<b>4</b>), [Zn₃(L²)₂­(bix)₃]_<i>n</i>·(H₂O)_4<i>n</i> (<b>5</b>), and [Zn₃(HL³)₂­(bix)₂]_<i>n</i> (<b>6</b>), where H₃L¹, H₃L², H₃L³ ligands represent 3-(2-carboxyphenoxy)­phthalic acid, 4-(2-carboxyphenoxy)­phthalic acid, 3-(4-carboxyphenoxy)­phthalic acid, respectively. Single crystal X-ray diffraction analysis reveals a three-dimensional (3D) network for <b>1</b> and <b>3</b>–<b>5</b> but a two-dimensional (2D) structure for <b>2</b> and <b>6</b>. Despite the construction from the polymetallic chains connected by the 4,4′-bpy ligands for both compounds <b>1</b> and <b>2</b>, a 3D architecture was revealed for the former species while a 2D configuration for the latter one. Complex <b>3</b> contains open nanotube building units composed of sole 44-numbered metallomacrocycles. For <b>4</b>, the 20-numbered metallomacrocycle subunits linked by Zn ions give a 1D chain, which further form a 3D polymeric structure with the help of the other cyclic-shaped subunits made from the bix ligands and Zn ions. A 3D framework of <b>5</b> is generated from the 2D sheets simplified as a (6,3) net bound by the bix ligands. Compound <b>6</b> shows a 2D corrugated framework simplified as a (4,4) net assembled by the bix ligand and dinuclear zinc unit as node. These results seem to suggest that the diversity in the building subunits formed in <b>1</b>–<b>6</b> actually originates from the intrinsic nature of the three asymmetric V-shaped tricarboxylate ligands together with the tunable coordination geometry and molecular configurations of ligands by the N-donor ligand employed. In addition, the thermal stability and luminescence properties for the series of six complexes have also been investigated

Chiral Discrimination of Diamines by a Binaphthalene-Bridged Porphyrin Dimer

A pair of 1,1′-binaphthalene-bridged bisporphyrins, (<i>R</i>)- and (<i>S</i>)-<b>H1</b>, were designed to examine their chiral discrimination abilities toward a range of model diamines by using UV–vis absorption, CD, and ¹H NMR spectroscopy with the assistance of DFT molecular modeling. The spectroscopic titrations revealed that (<i>R</i>)-/(<i>S</i>)-<b>H1</b> could encapsulate (<i>R</i>)-/(<i>S</i>)-DACH and (<i>R</i>)-/(<i>S</i>)-PPDA in the chiral bisporphyrin cavities, leading to the selective formation of sandwich-type 1:1 complexes via dual Zn–N coordination interactions. In particular, the chiral recognition energy (ΔΔ<i>G</i>°) toward (<i>R</i>)-/(<i>S</i>)-DACH was evaluated to be −4.02 kJ mol^–1. The binding processes afforded sensitive CD spectral changes in response to the stereostructure of chiral diamines. Remarkable enantiodiscrimination effects were also detected in the NMR titrations of (<i>R</i>)-/(<i>S</i>)-<b>H1</b>, in which the nonequivalent chemical shift (ΔΔδ) can reach up to 0.57 ppm for (<i>R</i>)-/(<i>S</i>)-DACH. However, due to the large steric effect, another chiral diamine ((<i>R</i>)-/(<i>S</i>)-DPEA) could not be sandwiched in the chiral bisporphyrin cavity; therefore, (<i>R</i>)-/(<i>S</i>)-DPEA could hardly be discriminated by (<i>R</i>)-/(<i>S</i>)-<b>H1</b>. The present results demonstrate a chiral bisporphyrin host with integrated CD and NMR chiral sensing functions and also highlight the binding-mode-dependent character of its enantiodiscrimination performance for different chiral guests

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] (<b>1</b>) and Dy₂[Pc­(OC₅H₁₁)₈]₂[Cor­(ClPh)₃] (<b>2</b>), 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 <b>1</b> 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

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 (<i>T</i>_B) of 30 K and large effective spin-reversal energy barrier of <i>U</i>_eff = 939 K, rendering it the best sandwich-type tetrapyrrole lanthanide SIM reported thus far