Multifunctionality in Two Families of Dinuclear Lanthanide(III) Complexes with a Tridentate Schiff-Base Ligand.

The employment of N-(2-carboxyphenyl)salicylideneimine in 4f metal chemistry has led to two families of dinuclear complexes depending on the lanthanide(III) used. Representative members exhibit interesting magnetic, optical, and catalytic properties.

Effects of plyometric training techniques on vertical jump performance of basketball players.

The aim of our study was to compare the effects of two different plyometric training programs (targeting knee extensors or plantar flexors) on jump height and strength of leg muscles. Twenty-nine male basketball players were assigned to the knee-flexed (KF), knee-extended (KE), or control groups. In addition to regular training, the KF group performed plyometric jumps (10 sets of 10 jumps, 3 sessions/week, 4 weeks) from 50 cm boxes with the knee flexed (90°-120°), whereas the KE group performed the jumps from 30 cm boxes with the knee much more extended (130°-170°). Jumping ability was evaluated with squat jumps (SJs), countermovement jumps (CMJs), and drop jumps from 20 cm (DJ20) and 40 cm (DJ40). Knee and ankle muscles were assessed during maximal isokinetic and isometric tests, and EMG activity was recorded from vastus lateralis and medial gastrocnemius. The KF group increased SJ (+10%, d = 0.86) and CMJ (+11%, d = 0.70) but decreased DJ40 height (-7%, d = -0.40). Conversely, the KE group increased DJ20 (+10%, d = 0.74) and DJ40 (+12%, d = 0.77) but decreased SJ height (-4%, d = -0.23). The reactivity index during DJs increased (+10% for DJ20, d = 0.47; +20% for DJ40, d = 0.91) for the KE group but decreased (-10%, d = -0.48) for the KF group during DJ40. Plantar flexor strength increased for the KE group (d = 0.72-1.00) but not for the KF group. Negative transfer across jumps is consistent with the principle of training specificity. Basketball players interested to perform fast rebounds in their training should avoid plyometric jumps with large knee flexions and long contact times.

Dinuclear lanthanide(III) complexes by metal-ion-assisted hydration of di-2-pyridyl ketone azine.

The initial employment of di-2-pyridyl ketone azine in 4f metal chemistry has led to a unique ligand transformation; the resulting anionic ligand is able to bridge two Ln(III) ions, affording neutral and cationic dinuclear complexes with interesting properties.

A family of dinuclear lanthanide(III) complexes from the use of a tridentate Schiff base.

The use of N-salicylidene-o-aminophenol (H2saph) in 4f-metal chemistry has led to the isolation of seven new isostructural lanthanide(iii) [Ln(III)] complexes. More specifically the Ln(NO3)3·xH2O/H2saph/Et3N (1 : 1 : 1) reaction mixtures in DMF/MeCN gave complexes [Ln2(NO3)2(saph)2(DMF)4] (Ln = Sm (); Eu (); Gd (); Tb (); Dy (); Ho (); Er ()) in good yields (∼65%). The structures of the isomorphous complexes and were solved by single-crystal X-ray crystallography; the other complexes are proposed to be isostructural with and based on elemental analyses, IR spectra and powder XRD patterns. The two Ln(III) atoms in the centrosymmetric molecules of and are doubly bridged by the deprotonated iminophenolato oxygen atoms of two nearly planar η(1):η(1):η(2):µ saph(2-) ligands. The imino nitrogen and five terminal oxygen atoms (the salicylaldiminate, two from one bidentate chelating nitrato group and two from two DMF ligands) complete square antiprismatic coordination at each metal centre. The IR spectra of the complexes are discussed in terms of the coordination modes of the ligands present in the complexes. Solid-state emission studies for all display identical ligand-based photoluminescence. Dc magnetic susceptibility studies in the 2-300 K range reveal the presence of a weak, intramolecular antiferromagnetic exchange interaction (J = -0.19(1) cm(-1) based on the spin Hamiltonian H = -J(SGd·SGd')) for and probably ferromagnetic exchange interaction within the molecules of and . Ac magnetic susceptibility measurements in zero dc field show temperature- and frequency-dependent out-of-phase signals with two well defined, thermally-activated processes for , suggesting potential single-molecule magnetism character. The Ueff value is 17.4 cm(-1) for the higher temperature process and 16.2 cm(-1) for the lower temperature one. The combination of photoluminescence and single-molecule behaviour in the Dy complex is critically discussed.

Dinuclear lanthanide(III)/zinc(II) complexes with methyl 2-pyridyl ketone oxime.

The first use of methyl 2-pyridyl ketone oxime (mpkoH) in zinc(II)/lanthanide(III) chemistry leads to the [ZnLn(mpko)3(mpkoH)3](ClO4)2 and [ZnLn(NO3)2(mpko)3(mpkoH)] families of dinuclear Zn(II)Ln(III) complexes displaying blue-green, ligand-based photoluminescence; the Zn(II)Dy(III) compound shows field-induced relaxation of magnetization.