Very Anisotropic 2D Molecular Magnetic Materials Based on Pentagonal Bipyramidal Heptacyanidorhenate(IV)

The first neutral 2D heterometallic assemblies based on orbitally degenerate heptacyanidorhenate(IV) were prepared and structurally characterized. An analysis of the magnetic data for the polycrystalline samples of Ph$_4$P[{Mn(acacen)}$_2$Re(CN)$_7$]·Solv (1) and PPN[{Mn(acacen)}$_2$Re(CN)$_7$]·Solv (2) have shown that both materials display slow magnetic relaxation at temperatures below 10 and 21 K for 1 and 2, respectively. Despite the presence of the same molecular magnetic modules that make up the anionic layers, the studied 2D networks differ significantly in magnetic anisotropy, having a small coercive field (0.115 T) for 1 and a large one (~2.5 T) for 2 at 2 K. In addition, for both polymers a M(H) value does not saturate at the maximum available field of 7 T, and the material 2 is a metamagnet. This intriguing difference originates from the cooperative anisotropic spin interaction in Re$^{IV}$−CN−Mn$^{III}$ pairs and the zero field splitting (ZFS) effect of Mn$^{III}$ ions with a noncollinear alignment of the local magnetic axes in crystals of the compounds

g-engineering in hybrid rotaxanes to create AB and AB2 electron spin systems: EPR spectroscopic studies of weak interactions between dissimilar electron spin qubits

Hybrid [2]rotaxanes and pseudorotaxanes are reported where the magnetic interaction between dissimilar spins is controlled to create AB and AB2 electron spin systems,allowing independent control of weakly interacting S =1=2 centers

Aplicación de la NOM-035 en una empresa de desarrollo de software

Dentro del PAP 3F09, Gestión del Cambio, del Talento Humano y la Efectividad Organizacional, se elaboró la continuación de apoyo con una empresa de desarrollo de software, para abarcar como propósito general el seguimiento de la aplicación de la guía de referencia número tres de la NOM 035, “Entorno Organizacional”. El alcance que el proyecto tuvo, fue de un total de 402 colaboradores, cumpliendo con el mínimo que la NOM requiere para su certificación. Utilizando una metodología cuantitativa, con la herramienta de cuestionario con preguntas tanto abiertas como cerradas. Posteriormente a la primera entrega de resultados al área de Recursos Humanos, se determinó que debían destacarse solamente aquellos dominios que fueran aspectos necesarios para identificar fácilmente a colaboradores con posible “burnout”. Por lo que, se concluyó, prestar mayor atención a las categorías de Siempre, Casi Siempre y Algunas veces. Al tomar estas en cuenta, se analizó que los dominios a los que se debía prestar mayor atención eran “Esfuerzo Mental”, “Jornada de Trabajo” y “Cantidad y ritmo de trabajo”. Con estas características se localizó el nombre de los colaboradores y se entregó una lista a los ejecutivos, para su debida intervención y atención. Aun así, consideramos estos resultados como no alarmantes, debido al giro de la empresa, sin embargo, se debe de monitorear y estar al tanto de manera frecuente, para evitar llegar a un posible “burnout”. Se recomendó a la empresa mantener un seguimiento y finalizar con la última guía de referencia faltante, para poder así concluir con las tres guías de la NOM 035.ITESO, A.C

Inorganic Approach to Stabilizing Nanoscale Toroidicity in a Tetraicosanuclear Fe18_{18}Dy6_{6} Single Molecule Magnet

Cyclic coordination clusters (CCCs) are proving to provide an extra dimension in terms of exotic magnetic behavior as a result of their finite but cyclized chain structures. The Fe$_{18}$Dy$_{6}$ CCC is a Single Molecule Magnet with the highest nuclearity among Ln containing clusters. The three isostructural compounds [Fe$_{18}$Ln$_{6}$(μ-OH)$_{6}$(ampd)$_{12}$(Hampd)$_{12}$(PhCO$_{2}$)$_{24}$](NO$_{3}$)$_{6}$·38MeCN for Ln = Dy$^{III}$ (1), Lu$^{III}$ (2), or Y$^{III}$ (3), where H$_{2}^{-}$ampd = 2-amino-2-methyl-1,3-propanediol, are reported. These can be described in terms of the cyclization of six {Fe$_{3}$Ln(μOH)(ampd)$_{2}$(Hampd)$_{2}$(PhCO$_{2}$)$_{4}$}$^{+}$ units with six nitrate counterions to give the neutral cluster. The overall structure consists of two giant Dy$_{3}$ triangles sandwiching a strongly antiferromagnetically coupled Fe$_{18}$ ring, leading to a toroidal arrangement of the anisotropy axis of the Dy ions, making this the biggest toroidal arrangement on a molecular level known so far

Single-molecule magnet behavior in 2,2 \u27-bipyrimidine-bridged dilanthanide complexes

A series of 2,2’-bipyrimidine-bridged dinuclear lanthanide complexes with the general formula [Ln(tmhd)3]2bpm (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate, bpm = 2,2’-bipyrimidine, Ln = Gd(III), 1; Tb(III), 2; Dy(III), 3; Ho(III), 4 and Er(III), 5) has been synthesized and characterized. Sublimation of [Tb(tmhd)3]2bpm onto a Au(111) surface leads to the formation of a homogeneous film with hexagonal pattern, which was studied by scanning tunneling microscopy (STM). The bulk magnetic properties of all complexes have been studied comprehensively. The dynamic magnetic behavior of the Dy(III) and Er(III) compounds clearly exhibits single molecule magnet (SMM) characteristics with an energy barrier of 97 and 25 K, respectively. Moreover, micro-SQUID measurements on single crystals confirm their SMM behavior with the presence of hysteresis loops

Observation of the influence of dipolar and spin frustration effects on the magnetocaloric properties of a trigonal prismatic {Gd-7} molecular nanomagnet

Pineda EM, Lorusso G, Zangana KH, et al. Observation of the influence of dipolar and spin frustration effects on the magnetocaloric properties of a trigonal prismatic {Gd-7} molecular nanomagnet. CHEMICAL SCIENCE. 2016;7(8):4891-4895.We report the synthesis and structure of a molecular {Gd-7} cage of the formula ((Pr2NH2)-Pr-i)(6)[Gd-7(mu(3)-OH)(3)(CO3)(6)((O2CBu)-Bu-t)(12)] which has crystallographic C-3h symmetry. Low temperature specific heat and adiabatic demagnetization experiments (the latter achieving temperatures below 100 mK), lead to the observation of the effects of both intramolecular dipolar interactions and geometric spin frustration. The dipolar interaction leads to a massive rearrangement of energy levels such that specific heat and entropy below 2 K are strongly modified while magnetic susceptibility and magnetization above 2 K are not affected. The consequences of these phenomena for low temperature magnetocaloric applications are discussed