Na Pan

Heteroleptic phthalocyaninato-[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth(III) triple-deckers: synthesis and spectroscopic characterization

Abstract The homo-dinuclear heteroleptic phthalocyaninato-[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth(III) triple-decker complexes (Pc)M[Pc(OC8H17)8]M[Pc(OC8H17)8] (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm) (1a–10a) and (Pc)M[Pc(OC8H17)8]M(Pc) (M=Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm) (2b–10b) were obtained by condensation of bis(phthalocyaninato) rare earths M[Pc(OC8H17)8]2 (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm), Li2(Pc) and M(acac)3·nH2O (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm). These novel compounds were characterized by 1H NMR, mass, electronic absorption (UV–Vis), and IR spectroscopic methods.

Raman spectroscopic characteristics of phthalocyanine and naphthalocyanine in sandwich-type phthalocyaninato and porphyrinato rare earth complexes.: Part 3. The effect of rare earth ionic size on the Raman characteristics of naphthalocyanine in bis(naphthalocyaninato) rare earth complexes

Abstract Raman spectroscopic data of a series of 13 sandwich double-decker bis(naphthalocyaninato) rare earth complexes M(2,3-Nc*) 2 [M=Ce⋯Lu except Nd and Pm, Y; Nc*=Nc( t Bu) 4 ] were collected using laser excitation sources emitting at 632.8 and 785 nm and systematically compared. The Raman characteristics for substituted naphthalocyaninato monoradical anion Nc* − under these two laser excitations are thus comparatively described. The strongly enhanced Raman band at approximately 1592 cm −1 , which is assigned to the naphthalene stretches of the Nc ring, is a typical feature of the monoanion radical, Nc* − under excitation with the 632.8 nm laser line. With laser excitation at 785 nm, which is nearly coincident with the Q band absorption of bis(naphthalocyaninato) rare earth complexes, the band at 1512–1530 cm −1 due to the CN (aza group) stretch is a good Raman marker band for the naphthalocyanine anion Nc* − . This band and the Nc breathings, naphthalene stretchings, isoindole stretchings, and coupling of pyrrole CC ring and aza CN stretches all shift to higher frequency with decreasing ionic radius (the rare earth contraction).

Electrochemistry of homoleptic bis[3(4),12(13),21(22),30(31)-tetra(tert-butyl)-naphthalocyaninato] rare earth(III) complexes

The electrochemistry of homoleptic bis(naphthalocyaninato) double-decker complexes for the whole series of tervalent rare earths M(TBNc)2 (M = Y, La…Lu except Ce and Pm; H2TBNc = 3(4),12(13),21(22),30(31)-tetra(tert-butyl)naphthalocyanine) has been systematically studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Up to three quasi-reversible one-electron oxidations and four quasi-reversible one-electron reductions have been revealed for these double-deckers.The half-wave potentials of all oxidations and the first reduction for double-decker complexes are dependent on the size of the metal center. The difference between the redox potentials of the first and second reductions for MIII(TBNc)2, which represents the potential difference between the first oxidation and first reduction of [MIII(TBNc)2]−, lies in the range 1.09-0.95 V and gradually diminishes along with the lanthanide contraction, indicating increased π-π interaction in the double-deckers in the same order. Comparison of...

Synthesis and liquid crystal behavior of bis[3,4,12,13,21,22,30,31-octa(dodecylthio)-2,3-naphthalocyaninato] rare earth complexes

A series of novel bis[3,4,12,13,21,22,30,31-octa(dodecylthio)-2,3-naphthalocyaninato] rare earth(III) complexes M[Nc(SC12H25)8]2(M = Nd, Eu, Gd, Tb, Y, Ho, Er) have been prepared by tetramerization of 2,3-bis(dodecylthio)-6,7-dicyanonaphthalene with M(acac)3·nH2O in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in refluxing n-octanol. These sandwich double-decker complexes were characterized by elemental analysis and various spectroscopic methods including UV-vis, near IR, IR, and mass spectroscopies. Their liquid crystal behavior was studied by polarized optical microscope (POM), differential scanning calorimeter (DSC), and X-ray diffraction. These alkylthio-substituted bis(2,3-naphthalocyaninato) rare earth complexes yield a hexagonal columnar liquid crystal whose stable temperature range is between 42 and 243°C. The stable temperature domain of the mesophase shows a trend to be dependent on the central rare earth ionic size. In contrast, the molecular packing of these complexes as revealed by X-ray diffraction was found to be almost independent of the ionic size of the central rare earth.