The enantiomers of N,N’–bis(1–phenylethyl)–2,6–pyridinedicarboxamide (L), namely (R,R)–1, and (S,S)–1, react with Ln(III) ions to give stable [LnL3]3+ complexes in anhydrous acetonitrile solution and in the solid state, as evidenced by ES–MS, NMR and luminescence titrations, and their X–ray crystal structures, respectively. All [LnL3]3+ complexes (Ln(III) = Eu, Gd, Tb, Yb, and L = (R,R)–1, and (S,S)–1)) are isostructural and crystallize in the cubic space group I23. Although the small quantum yields of the Ln(III)–centered luminescence clearly point to the poor efficiency of the luminescence sensitization by the ligand and the intersystem crossing (ISC) and ligand–to–metal energy transfers, the ligand triplet–excited–state energy seems relatively well suited to sensitize many Ln(III) ion’s emission, for instance, in the VIS (Eu, Tb), NIR (Nd, Yb), or in both regions (Pr, Sm, Dy, Er, Tm).

The chiral nonaazamacrocyclic amine L, which is a reduction product of the 3+3 Schiff base macrocycle, wraps around the lanthanide(III) ions to form enantiopure helical complexes. These Ce(III), Pr(III), Nd(III), Eu(III), Gd(III), Tb(III), Er(III), Yb(III) and Lu(III) complexes have been isolated in enantiopure form and have been characterized by spectroscopic methods. X-ray crystal structures of the Ln(III) complexes with L show that the thermodynamic product of the complexation of the RRRRRR-isomer of the macrocycle is the (M)-helical complex in the case of Ce(III), Pr(III), Nd(III) and Eu(III). In contrast, the (P)-helical complex is the thermodynamic product in the case of Yb(III) and Lu(III). The NMR and CD spectra show that the (M)-helicity for the kinetic complexation product of the RRRRRR-isomer of the macrocycle is preferred for all investigated lanthanide(III) ions, while the preferred helicity of the thermodynamic product is (M) for the early lanthanide(III) ions and (P) for the late lanthanide(III) ions. In the case of the late lanthanide(III) ions, a slow inversion of helicity between the kinetic (M)-helical product and the thermodynamic (P)-helical product is observed in solution. For Er(III), Yb(III) and Lu(III) both forms have been isolated in pure form and characterized by NMR and CD. The analysis of 2D NMR spectra of the Lu(III) complex reveals the NOE correlations that prove that the helical structure is retained in solution. The NMR spectra also reveal large isotopic effect on the 1H NMR shifts of paramagnetic Ln(III) complexes, related to NH/ND exchange. Photophysical measurements show that LRRRRRR appears to favour an efficient 3ππ*-to-Ln energy transfer process taking place for Eu(III) and Tb(III), but these Eu(III)- and Tb(III)-containing complexes with LRRRRRR lead to small luminescent quantum yields due to an incomplete intersystem crossing (isc) transfer, a weak efficiency of the luminescence sensitization by the ligand, and/or efficient non-radiative deactivation processes. Circularly polarized luminescence on the MeOH solutions of Eu(III) and Tb(III) complexes confirms the presence of stable chiral emitting species and the observation of almost perfect mirror-image CPL spectra for these compounds with both enantiomeric forms of L.

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Single crystalline-like thin film samples of the ferromagnetic shape memory alloy Fe7Pd3 enable studying the physics of this promising material system. We demonstrate how to grow such samples with electron beam evaporation and investigate the influence of variable deposition parameters, focusing hereby on substrate temperature and deposition interruptions. We are able to produce Fe7Pd3 thin film samples of 500 nm in thickness in austenitic and martensitic phases and the latter with twinning structures visible at the sample surface. The ideal substrate temperature turns out to be around 700 °C, whereas deposition at temperatures below 690 °C leads to sample demixing, while film quality is decreased at higher temperatures because of lattice misfit effects. In the case of direct substrate heating by heat radiation, comparable sample quality is accomplishable if numerous deposition interruptions are included in the growth procedure to homogenize surface temperature so that comparable effective material diffusion, i.e., material relaxation, is achieved. Our investigations resulted in identifying a quite easily realizable deposition procedure to grow samples of satisfyingly good quality with closed surfaces and without the need for subsequent processing.

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