Lanthanides, phthalocyanine complexes

Cf produces two fission products that travel in opposite directions. If one projectile hits the sample, ions will be produced. These ions may then be focused and measured by TOF MS. The other projectile may be used to measure the start of the ionization process. This method has been used to study the ions produced from the ionization of metal complexes such as cadmium thiolates (33) and lanthanide phthalocyanine complexes (34). This method has also been used on metal oxides such as La203 to produce metal oxide cluster ions (35). 

The lanthanide phthalocyanine complexes, obtained by conventional methods starting from metal salts at 170-290°C and phthalonitrile (Example 26), contain one or two macrocycles for each metal atom [5,6,8,63,82,84-98]. Thus, according to Refs. 6,63, and 85, the complexes having compositions LnPc2H, XLnPc (X- is halide anion), and Ln2Pc3 (a super-complex ) were prepared from phthalonitrile as a precursor the ratio of the reaction products depends on the synthesis conditions and the metal nature. The ionic structure Nd(Pc)+Nd(Pc)2 was suggested [85] and refuted [63] for the neodymium super-complex Nd2Pc3 the covalent character of the donor-acceptor bonds in this compound and other lanthanide triple-decker phthalocyanines was proved by the study of dissociation conditions of these compounds [63]. 

To date there has been no report of observation of magnetic order of 4/ metal phthalocyanines in solid state. However, in 2003, it was revealed that some of lanthanide phthalocyanine complexes exhibit an intriguing property as SMM, a relatively new class of magnetic compounds [29,30], The SMMs are the paramagnetic... 

Scheme 8.1 Three key methods of the synthesis of lanthanide(lll) bis(phthalocyanine) complexes. Homoleptic complexes symmetrical (A, B) and unsymmetrical (C1 and C2, D1). Thereby, the thermal fusion group A can be subdivided into (A1) solvent free fusion (A2) refluxing in the mixture of protic solvents in the presence of organic base - DBU and (A3) MW assisted fusion.

The template methods have also been used for the synthesis of a number of substituted Ln di(naphthalocyanine) complexes, LnNc2 [82-88]. Apart from thermal fusion by conventional heating processes, complexation has been initiated by microwave radiation, although only a few publications are devoted to the template synthesis of lanthanide bis(phthalocyanine) complexes by this method [89, 90]. The use of microwave radiation (MW) reduces the reaction time from several hours to several minutes. Unsubstituted complexes LnPc2 (Ln = Tb, Dy, Lu) were prepared [90] by irradiation (650-700 W) of a mixture of phthalonitrile with an appropriate lanthanide salt for 6-10 min (yields >70%). 

Lanthanide phthalocyanines may be prepared by heating the metal chlorides468 or formates469 with 1,2-cyanobenzamide, 1 1 complexes, for example Er(pc)Cl, being the products. An alternative and better route used phthalonitrile (equation 8)., 471... 

These complexes, unlike the crown ether complexes but similar to the aza-crown and phthalocyanine complexes, are fairly stable in water. Their dissociation kinetics have been studied and not surprisingly they showed marked acid catalysis.504 Association constant values for lanthanide cryptates have been determined.505,506 A study in dimethyl sulfoxide solution by visible spectroscopy using murexide as a lanthanide indicator showed that there was little lanthanide specificity (but surprisingly the K values for Yb are higher than those of the other lanthanides). The values are set out in Table 9.507... 

The lanthanide phthalocyanines (Fig. 5.2) can also be obtained from the corresponding metal salts and metal-free phthalocyanine or 1,3-D [6], It has been established [6,86] that whereas a diphthalocyanine complex Pc2LnH is mainly obtained for the heaviest lanthanides (Dy-Lu), a super-complex Pc3Ln2 is progressively... 

Porphyrin complexes were first sythesized in 1971 [224] and further studied in 1974 with a view to exploit a new class of lanthanide shift reagents [225]. Publication of the intrinsic properties of the phthalocyanine counterparts shed new light on this class. While the study of the phthalocyanine complexes was hampered by their low solubility the Por analogues are generally more accessible to a wider range of solvents, thus leading to improved crystallization conditions [226]. To optimize the crystallization behavior a couple of substituted porphyrins have been examined (Table 18) [226-234]. 

In what follows, the first section is devoted to describing transition-metal Pc complex-based ferromagnets and also other related complexes exhibiting no ferromagnetic order. The second section describes the magnetic interaction of n-radical phthalocyanines in crystals. In the last section, we present Pc-based SMMs and a general discussion on magnetism and electronic structure of lanthanide Pc complexes. 

Ishikawa, N., lino, T., and Kaizu, Y. (2002) Determination of Ugand-field parameters and f-electronic stractures of hetero-dinuclear phthalocyanine complexes with a diamagnetic yttrium(lll) and a paramagnetic trivalent lanthanide ion. Journal of Physical Chemistry A., 106, 9543-9550. 

Synthetic, spectroscopic, and theoretical study of novel supramolecular structures composed of lanthanide phthalocyanine double-decker complexes 02CCR (226)93. 

In 2003 a new class of SMMs was reported which contain only a single paramagnetic metal ion. These were the feis-phthalocyanine (H2PC) lanthanide sandwich complexes (Bu4N)[L (Pc)2], where the ion has... 

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