Design, Synthesis And Properties Of Novel Phthalocyanine Compounds And Derivatives

Phthalocyanines, which have a cyclic tetrapyrrole molecular, are important kinds of dyes and pigments with significant industrial application. As the typical representative of functional molecular with macrocyclic structures, phthalocyanines have good coordination ability, and most of the periodic table metal ion reactions can be their metal compounds (e.g. lanthanides. actinides. and some main group elements). In particular, coordination with large metal centers leads to the formation of sandwich-type phthalocyaninato metal complexes. These complexes exhibit great potential in the fields of molecular magnets, molecular-based multibit information storage, field effect transistors, non-liner optical materials and molecular machines owing to the intramolecular π-π interactions and the intrinsic nature of the metal centers. As a part of phthalocyanine derivatives, subphthalocyanines have attracted significant research interests over the last two decades due to their interesting electronic and fluorescence properties. In this thesis a series of novel sandwich-type tetrakis(phthalocyaninato) compounds, novel conjugated multiplenuclear phthalocyanines and novel chiral subphthalocyanine derivatives have been designed and synthetized, with their structures and properties well researched. The following four topics are the main research contents:1 Design, Synthesis, and Properties of Sandwich-type Tetrakis(phthalocyaninato) Rare Earth(Ⅲ)-Cadmium(Ⅱ) Quadruple-deckersSandwich-type phthalocyaninato metal compounds have been revealed to exhibit tunable spectroscopic, electronic, redox, and magnetic properties originating from the nature of the macrocyclic ligands and the metal centers. However, studies over the sandwich-type multi(phthalocyaninato) metal compounds had stopped at the point of double-and triple-deckers for quite a long period associated with the limitation in the selection of appropriate metal ion with suitable coordination number and geometry, charge, hard and soft acidic and basic behavior to match the coordination algorithm of phthalocyanines. To extend this system, typical sandwich-type tetrakis(tetrapyrrole) metal complexes revealed quadruple-decker molecular configuration were prepared by condensation of bis(tetrapyrrole) rare earth double-deckers in the presence of divalent cadmium ion. In this section, for the purpose of extensive studies, we describe herein the spectroscopic. electrochemical, and nonlinear optical properties of a series of homoleptic tetrakis[2,3.9.10.16.17.23.24-octa(octyloxy)phthalocyaninato] rare earth-cadmium quadruple-decker compounds {[Pc(OC8H17)8]M[Pc(OC8H,7)8]Cd[Pc(OC8H17)8]M[Pc(OC8H17)8]} (M= Y. Pr-Yb except Pm) (1-12). Systematic studies over the synthesis of the sandwich-type compounds of the whole series of lanthanide metals and yttrium clearly reveal the dependence of the formation and isolation of target quadruple-deckers on the rare earth ionic size, i.e. the lanthanide contraction effect, which is supported by the electronic absorption result. In particular, comparative electrochemical investigations between the lanthanide and yttrium quadruple-deckers reveal the contribution of f-electrons, actually the f-f interactions between the lanthanide metal centers separated by divalent cadmium ion in the tetrakis(phthalocyaninato) lanthanide-cadmium compounds, to their electrochemical behavior.2 Synthesis, Structure, Spectroscopic, and Single-molecule Magnetic Properties of Sandwich-type Tetrakis(phthalocyaninato) Dysprosium(Ⅲ)-Cadmium(Ⅱ) Quadruple-decker CompoundsBoth lanthanide-and transition-metal-based single-molecule magnets (SMMs) have attracted increasing research interest because of their potential applications in magnetic storage and molecular spintronics associated with the magnetic bistability. Limited studies conducted thus far suggest the magnetic exchange interaction on the SMM behavior of the lanthanide-based compounds without concerning the contribution from the coordination geometry of an individual lanthanide ion and vice versa. Obviously, suitable polylanthanide SMM systems that allow studies toward clarifying the contribution of the coordination geometry and/or f-f magnetic interaction are highly desired. The availability of sandwich-type multinuclear rare-earth compounds with mixed tetrapyrrole rings provides a good chance to work for this target owing to the inherent advantage in modulating the rare-earth ions and tuning the coordination geometry for lanthanide ions and f-f magnetic interaction. In this section, with the aim of tuning and controlling the molecular structure (actually the coordination geometry of the dysprosium spin carrier), two new tetrakis(phthalocyaninato) metal quadruple-decker compounds{(Pc)Dy[Pc(OC5H11)8]Cd[Pc(OC5H11)8]Dy(Pc)} (1) and{[Pc(OC5H11)8]Dy[Pc(OC5H11)8]Cd[Pc(OCsH11)8]Dy[Pc(OC5H11)8]} (2) {H2Pc= unsubstituted phthalocyanine; 2,3,9,10,16,17,23,24-octakis(pentyloxy)phthalocyanine} with different extent of peripheral substitution for the phthalocyanine ligands have been designed and prepared from corresponding neutral bis(phthalocyaninato) dysprosium double-decker{(Pc)Dy[Pc(OCsH11)8]} or{[Pc(OC5H11)8]Dy[Pc(OC5H11)8]}. respectively. Single crystal X-ray diffraction analysis clearly reveals the different skew angle for the bis(phthalocyaninato) dysprosium unit in these two quadruple-decker compounds. This in turn results in their obvious different SMM behavior according to magnetic measurements, not only revealing the structure-magnetic property relationship but more importantly providing an easy but effective way towards effectively tuning the SMM behavior of tetrakis(phthalocyaninato) lanthanide quadruple-deckers through simple peripheral substitution.3 Design, Synthesis, and Properties of Multinuclear Phthalocyanine-fused Molecular NanoarraysDeveloping new conjugated 2D carbon materials with well defined composition and structure becomes highly desired. Due to their intrinsic photonic, electronic, chemical, and physical properties, both porphyrins and phthalocyanines with planar conjugated skeleton appear to be good building block for the construction of new conjugated 2D materials. Despite the still lack of truly tetrapyrrole-fused 2D material at this stage, the effort paid towards this direction has resulted in a series of multinuclear porphyrin/phthalocyanine-fused molecular arrays with further extended conjugated system. Due to the limited choice of tetracyanobenzene precursors, the so-far reported phthalocyanine-fused molecular arrays have also been limited to the scope of benzene/naphthalene/anthracene-bridged bi/trinuclear systems with either linear or triangular shape. As a result, developing new strategy towards preparing novel mucltinuclear phthalocyanine-fused derivatives with novel molecular skeletons becomes highly desired in this field. In this section, a new "post-tetrapyrrole treatment" strategy has been developed for the synthesis of novel conjugated multiplenuclear phthalocyanine-fused arrays with unsymmetrical diamino substituted phthalocyanine as starting material, not only extending the multiplenuclear phthalocyanine-fused arrays and more importantly making one step further forward towards the tetarpyrrole-based conjugated two-dimensional materials with well defined composition and structure, nitrogen-containing conjugated nature, tuneable central metal ions, and therefore extensive application potentials in a wide range of fields.4 Design, Synthesis, and Properties of the first five-membered-heterocycles-fused subphthalocyanine derivatives:Chiral tri(benz[b]thiopheno)subporphyrazinesDuring the period of early 1970s in continuously developing novel phthalocyanine compounds. For the purpose of producing boron phthalocyanine compound, an unexpectedly tripyrrolic compound with the cone-shaped 14 π-electron conjugated core was isolated which has been well known as subphthalocyanine (SubPc). Because of the interesting electronic and fluorescence properties and unique role in leading to the unsymmetric A3B type phthalocyanine derivatives, these ring-contracted analogues of phthalocyanines have attracted significant research interests in particular over the past two decades. In a similar manner to developing phthalocyanine-related molecular materials, modification over the molecular skeleton of SubPc also led to a number of subporphyrazines (SubPzs) and subnaphthalocyanines (SubNcs). However, unlike the case of phthalocyanines, the five-membered-heterocycles-fused subphthalocyanine analogue still remains unreported thus far. In the present paper, we describe the synthesis, spectroscopic, and electrochemical properties of the first flve-membered-heterocycles-fused subphthalocyanine analogues. tri(benzo[b]thiopheno)subporphyrazines with C3 and C1 molecular symmetry, respectively, BTSubPz(OPh)-(.3 (1) and BTSubPz(OPh)-C, (2), in which the benzo[b]thiophene moieties are fused from their 2,3-sites to the subporphyrazine core, Scheme 1. Fortunately, chiral HPLC isolation eventually led to two pairs of optically resolved chiral enantiomers R1/S1 and R2/S2, Figures 1 and S1 (Supporting Information). Nevertheless, the relationship between the CD signal and conformation for both chiral diastereomers was clearly elucidated on the basis of theoretical calculations. The present result will be surely helpful for the design and synthesis of not only novel subphthalocyanine analogues but also their chiral counterparts.