41 research outputs found
Design of pure heterodinuclear lanthanoid cryptate complexes
Heterolanthanide complexes are difficult to synthesize owing to the similar chemistry of the lanthanide ions. Consequently, very few purely heterolanthanide complexes have been synthesized. This is despite the fact that such complexes hold interesting optical and magnetic properties. To fine-tune these properties, it is important that one can choose complexes with any given combination of lanthanides. Herein we report a synthetic procedure which yields pure heterodinuclear lanthanide cryptates LnLn*LX(3) (X = NO(3)(â) or OTf(â)) based on the cryptand H(3)L = N[(CH(2))(2)N[double bond, length as m-dash]CHâRâCH[double bond, length as m-dash]Nâ(CH(2))(2)](3)N (R = m-C(6)H(2)OH-2-Me-5). In the synthesis the choice of counter ion and solvent proves crucial in controlling the LnâLn* composition. Choosing the optimal solvent and counter ion afford pure heterodinuclear complexes with any given combination of Gd(iii)âLu(iii) including Y(iii). To demonstrate the versatility of the synthesis all dinuclear combinations of Y(iii), Gd(iii), Yb(iii) and Lu(iii) were synthesized resulting in 10 novel complexes of the form LnLn*L(OTf)(3) with LnLn* = YbGd 1, YbY 2, YbLu 3, YbYb 4, LuGd 5, LuY 6, LuLu 7, YGd 8, YY 9 and GdGd 10. Through the use of (1)H, (13)C NMR and mass spectrometry the heterodinuclear nature of YbGd, YbY, YbLu, LuGd, LuY and YGd was confirmed. Crystal structures of LnLn*L(NO(3))(3) reveal short LnâLn distances of âź3.5 Ă
. Using SQUID magnetometry the exchange coupling between the lanthanide ions was found to be anti-ferromagnetic for GdGd and YbYb while ferromagnetic for YbGd
Vibrational Spectroscopic Characteristics of Phthalocyanine and Naphthalocyanine in Sandwich-type Phthalocyaninato and Porphyrinato Rare Earth Complexes Part 11 - Raman Spectroscopic Characteristics of Phthalocyanine in Mixed [tetrakis(4-chlorophenyl
Raman spectroscopic data in the range of 500-1800 cm-1 for a series of 15 mixed \[tetrakis(4-chlorophenyl)porphyrinato](phthalocyaninato) double-decker complexes with tervalent rare earths MIII(TClPP)(Pc) (M = Y, La...Lu except Ce and Pm) and intermediate-valent cerium Ce(TClPP)(Pc) have been collected using laser excitation sources emitting at 632.8 and 785 nm. Comparison with the Raman spectra of corresponding bis phthalocyaninato) rare earths reveals that the Raman characteristics of mixed ring double-deckers are dominated by the phthalocyaninato-metal fragment M(Pc) and phthalocyanine exists as monoradical anion Pcâ˘- in MIII(TClPP)(Pc) and dianion Pc2- in Ce(TClPP)(Pc), respectively. Under excitation at 632.8 nm that is in close resonance with the main Q absorption band of phthalocyanine ligand, typical Raman marker band of the monoanion radical Pcâ˘- was observed at 1512-1519 cm-1 as a weak band resulting from the coupling of pyrrole C=C and aza C=N stretchings. For Ce(TClPP)(Pc), a strong band at 1492 cm-1 with contributions from both pyrrole C=C and aza C=N stretchings as well as the isoindole stretching was the marker Raman band of Pc2-. When excited with laser radiation of 785 nm, which is far away from the main Q absorption band of the phthalocyanine ligand, the marker Raman band of Pcâ˘- in MIII(TClPP)(Pc) is observed at 1495-1514 cm-1 and of Pc2- in Ce(TClPP)(Pc) at 1511 cm-1 as a strong band