Ladder-like heteropolynuclear assemblies via cyanido bridges and platinum(II)-thallium(I) bonds: structural and photophysical properties.

We describe the mononuclear anionic cyanido-pentafluorophenyl complexes, (NBu4)[Pt(C^N)(C6F5)(CN)] [C^N = 7,8-benzoquinolate (bzq) 1, 2-(2,4-difluorophenyl)pyridinate (dfppy) 2] and the heteropolynuclear derivatives [{Pt(C^N)(C6F5)(CN)}Tl] (C^N = bzq 3, dfppy 4). These complexes were synthesized via a two-step modular synthesis by reaction of the corresponding potassium salts K[Pt(C^N)(C6F5)(CN)], prepared in situ from [Pt(C^N)(C6F5)(DMSO)] and KCN in acetone/H2O, with TlPF6. The structures of {[Pt(bzq)(C6F5)(CN)Tl]·THF}n (3·THF)n and [{Pt(dfppy)(C6F5)(CN)}Tl]4·dioxane [4]4·dioxane, determined by X-ray crystallography, confirm the presence of Pt(II)-Tl(I) bonds [2.9795(6)-3.0736(3) Å], but in the dfppy complex, the incorporation of dioxane, causes a significant structural change. Thus, whereas [3·THF]n achieves a bent-ladder shape extended double chain Tl⋯[Pt⋯Tl]n⋯Pt supported by lateral bridging [Pt](µ-CN)[Tl] ligands, [4]4·dioxane is formed by discrete Pt4Tl4 rectangular aggregates stabilized by [Pt](µ-CN)[Tl] and Pt⋯Tl bonds, which are connected by dioxane bridging molecules through Tl⋯O(dioxane) additional contacts. Solid state emissions are redshifted compared with the mononuclear derivatives 1 and 2 and have been assigned, with the support of theoretical calculations on Pt4Tl4 models, to metal-metal'-to-ligand charge transfer (3MM'LCT [d/s σ*(Pt, Tl) → π*(C^N)]) for 3 and mixed 3MM'LCT/3IL for 4. In fluid THF solution, the complexes are not emissive. At 77 K, 3 and 4 exhibit bright emissions attributed to the formation of bimetallic [{Pt(C^N)(C6F5)(CN)}Tl(THF)x], and anionic [Pt(C^N)(C6F5)(CN)]- fragments. Furthermore, both 3 and 4 exhibit a reversible mechanochromism with a red shift of the emissions upon crushing, suggesting some degree of shortening of metal-metal separation. Finally, complex 3 shows solvatochromic behavior with color/luminescence changes by treatment with a drop of MeOH, CH2Cl2, THF or Et2O, with shifts from 583 in 3-MeOH to 639 nm in 3-THF. However, 4 only demonstrates a bathochromic response to MeOH.

Phenylbenzothiazole-Based Platinum(II) and Diplatinum(II) and (III) Complexes with Pyrazolate Groups: Optical Properties and Photocatalysis.

Based on 2-phenylbenzothiazole (pbt) and 2-(4-dimethylaminophenyl)benzothiazole (Me2N-pbt), mononuclear [Pt(pbt)(R'2-pzH)2]PF6 (R'2-pzH = pzH 1a, 3,5-Me2pzH 1b, 3,5-iPr2pzH 1c) and diplatinum (PtII-PtII) [Pt(pbt)(µ-R'2pz)]2 (R'2-pz = pz 2a, 3,5-Me2pz 2b, 3,5-iPr2pz 2c) and [Pt(Me2N-pbt)(µ-pz)]2 (3a) complexes have been prepared. In the presence of sunlight, 2a and 3a evolve, in CHCl3 solution, to form the PtIII-PtIII complexes [Pt(R-pbt)(µ-pz)Cl]2 (R = H 4a, NMe2 5a). Experimental and computational studies reveal the negligible influence of the pyrazole or pyrazolate ligands on the optical properties of 1a-c and 2a,b, which exhibit a typical 3IL/3MLCT emission, whereas in 2c the emission has some 3MMLCT contribution. 3a displays unusual dual, fluorescence (1ILCT or 1MLCT/1LC), and phosphorescence (3ILCT) emissions depending on the excitation wavelength. The phosphorescence is lost in aerated solutions due to sensitization of 3O2 and formation of 1O2, whose determined quantum yield is also wavelength dependent. The phosphorescence can be reversibly photoinduced (365 nm, ∼ 15 min) in oxygenated THF and DMSO solutions. In 4a and 5a, the lowest electronic transitions (S1-S3) have mixed characters (LMMCT/LXCT/L'XCT 4a and LMMCT/LXCT/ILCT 5a) and they are weakly emissive in rigid media. The 1O2 generation property of complex 3a is successfully used for the photooxidation of p-bromothioanisol showing its potential application toward photocatalysis.

A new family of luminescent [Pt(pbt)2(C6F5)L]n+ (n = 1, 0) complexes: synthesis, optical and cytotoxic studies.

Given the widely recognized bioactivity of 2-arylbenzothiazoles against tumor cells, we have designed a new family of luminescent heteroleptic pentafluorophenyl-bis(2-phenylbenzothiazolyl) PtIV derivatives, fac-[Pt(pbt)2(C6F5)L]n+ (n = 1, 0) [L = 4-Mepy 1, 4-pyridylbenzothiazole (pybt) 2, 4,4'-bipyridine (4,4'-bpy) 3, 1,2-bis-(4-pyridyl)ethylene (bpe) 4 (E/Z ratio: 90/10), 1,4-bis-(pyridyl)butadiyne (bpyb) 5, trifluoroacetate (-OCOCF3) 6] and a dinuclear complex [{Pt(pbt)2(C6F5)}2(µ-bpyb)](PF6)27, in which the trans ligand to the metalated C-(pbt) was varied to modify the optical properties and lipophilicity. Their photophysical properties were systematically studied through experimental and theoretical investigations, which were strongly dependent on the identity of the N-bonded ligand. Thus, complexes 1, 3 and 6 display, in different media, emission from the triplet excited states of primarily intraligand 3ILCT nature localized on the pbt ligand, while the emissions of 2, 5 and 7 were ascribed to a mixture of close 3IL'(N donor)/3ILCT(pbt) excited states, as supported by lifetime measurements and theoretical calculations. Irradiation of the initial E/Z mixture of 4 (15 min) led to a steady state composed of roughly 1 : 1.15 (E : Z) and this complex was not emissive at room temperature due to an enhanced intramolecular E to Z isomerization process of the 1,2-bis-(4-pyridyl)ethylene ligand. Complexes 1-3 and 6 showed excellent quantum yields for the generation of singlet oxygen in aerated MeCN solution with the values of ϕ(1O2) ranging from 0.66 to 0.86 using phenalenone as a reference. Cationic complexes 1-3 exhibited remarkable efficacy in the nanomolar range against A549 (lung carcinoma) and HeLa (cervix carcinoma) cell lines with notable selectivity relative to the non-tumorigenic BEAS-2B (bronchial epithelium) cells. In the A549 cell line, the neutral complex 6 showed low cytotoxicity (IC50: 29.40 µM) and high photocytotoxicity (IC50: 5.75) when cells were irradiated with blue light for 15 min. These complexes do not show evidence of DNA interaction.

Phosphorescent 2-phenylbenzothiazole PtIV bis-cyclometalated complexes with phenanthroline-based ligands.

We describe a family of dicationic heteroleptic complexes of the type [Pt(pbt)2(N^N)]Q2, bearing two cyclometalating 2-phenylbenzothiazole (pbt) groups and a N^N phenanthroline-based ligand [N^N = 1,10-phenanthroline (phen) 4, pyrazino[2,3-f][1,10]-phenanthroline (pyraphen) 5, 5-amine-1,10-phenanthroline (NH2-phen) 6], with two different counteranions (Q = CF3CO2 and PF6). Complexes 4-6-PF6 and 4-6-CF3CO2 were obtained through ligand substitution from cis-[Pt(pbt)2Cl2] 2 and cis-[Pt(pbt)2(OCOF3)2] 3, respectively. The molecular structures of 2, 3 and 4-PF6 and the photophysical and electrochemical properties of all complexes were studied in detail. The precursors 2 and 3 exhibit high-energy emissions from 3IL excited states centered on the cyclometalated pbt, with lower efficiency in 2 in relation to 3 by the presence of closer thermally accessible deactivating 3LMCT excited states in 2. The PtIV complexes 4-5-CF3CO2/PF6 display orange emission in CH2Cl2 solution, solid state (298, 77 K) or PS films, arising from a 3IL(pbt) emissive state. The NH2-phen derivatives 6-CF3CO2/PF6 show dual emission associated to two close different emissive states, 3IL'CT (L' = NH2-phen) and 3IL(pbt), depending on the medium and the excitation wavelength. DFT and time-dependent TD-DFT calculations support these assignments and allow explain the luminescence of these tris-chelate PtIV complexes.

Luminescent Anionic Cyclometalated Organoplatinum (II) Complexes with Terminal and Bridging Cyanide Ligand: Structural and Photophysical Properties.

We present the synthesis and characterization of two series of mononuclear heteroleptic anionic cycloplatinated(II) complexes featuring terminal cyanide ligand Q+[Pt(C^N)(p-MeC6H4)(CN)]- [C^N = benzoquinolate (bzq), Q+ = K+ 1 and NBu4+ 4; 2-phenylpyridinate (ppy), Q+ = K+ 2 and NBu4+ 5 and 2-(2,4- difluorophenyl)pyridinate (dfppy), Q+ = K+ 3 and NBu4+ 6] and a series of symmetrical binuclear complexes (NBu4)[Pt2(C^N)2(p-MeC6H4)2(µ-CN)] (C^N = bzq 7, ppy 8, dfppy 9). Compounds 5, 6, and 7-9 were further determined by single-crystal X-ray diffraction. There are no apparent intermolecular Pt···Pt interactions owing to the presence of bulky NBu4+ counterion. Slow crystallization of K[Pt(ppy)(p-MeC6H4)(CN)] 2 in acetone/hexane evolves with formation of yellow crystals, which were identified by single-crystal X-ray diffraction methods as the salt complex {[Pt(ppy)(p-MeC6H4)(CN)]2K3(OCMe2)4(µ-OCMe2)2}[Pt(ppy)(p-MeC6H4)(µ-CN)Pt(ppy)(p-MeC6H4)]·2acetone (10), featuring the binuclear anionic unit 8- neutralized by an hybrid inorganic-organometallic coordination polymer {[Pt(ppy)(p-MeC6H4)(CN)]2K3(OCMe2)4(µ-OCMe2)2}+. The photophysical properties of all compounds were recorded in powder, polystyrene film, and solution states with a quantum yield up to 21% for 9 in the solid state. All complexes displayed bright emission in rigid media, and for the interpretation of their absorption and emission properties, density functional theory (DFT) and time-dependent DFT calculations were applied.

Polymorphism and Mechanochromism in 2-Phenylbenzothiazole Cyclometalated PtII Complexes with Chelating N∧O Ligands.

New cyclometalated PtII complexes with 2-phenylbenzothiazole (pbt) and two different picolinate ligands [Pt(pbt)(R-pic-κN,O)] (R = H (1), OH (2)) were prepared. In contrast to 1, the OH substituent group on 2 allows modulation of the packing in the solid state through donor-acceptor H-bonding interactions with the CH2Cl2 solvent. Thus, three pseudopolymorphs of 2 with different aggregation degrees were isolated, including yellow 2-Y, orange-red 2-R (2·0.5CH2Cl2) and black 2-B (2·0.75CH2Cl2) with emissions at 540, 656, and 740 nm, respectively, in the solid state at 298 K. 2-R and 2-B can be transformed to the pristine solid 2. Studies of their crystal structures show that 1 and 2-Y stack in columns with only π···π stacking interactions, whereas 2-R displays strong aggregated 1D infinite chains based on Pt···Pt and π···π stacking interactions, consistent with the colors and the photophysical properties, measured in several media. Interestingly, 1 and 2 exhibit reversible mechanochromic behavior with high contrast in the color and color emission upon mechanical grinding due to a phase transition between a crystalline and an amorphous state, as confirmed by powder X-ray diffraction (PXRD) studies. Theoretical calculations indicate that Pt···Pt contacts are more relevant in the trimers and tetramers than in the dimers, particularly in their T1 states, associated with a change from a 3IL/3MLCT transition in the monomer to 3MM(L+L')CT in the oligomers. Noncovalent interaction (NCI) theoretical studies indicate that the π···π stacking among chelates also exerts a strong influence in the metal-metal-to-ligand charge transfer transition character.

Dynamic Packet Duplication for Industrial URLLC.

The fifth-generation (5G) network is presented as one of the main options for Industry 4.0 connectivity. To comply with critical messages, 5G offers the Ultra-Reliable and Low latency Communications (URLLC) service category with a millisecond end-to-end delay and reduced probability of failure. There are several approaches to achieve these requirements; however, these come at a cost in terms of redundancy, particularly the solutions based on multi-connectivity, such as Packet Duplication (PD). Specifically, this paper proposes a Machine Learning (ML) method to predict whether PD is required at a specific data transmission to successfully send a URLLC message. This paper is focused on reducing the resource usage with respect to pure static PD. The concept was evaluated on a 5G simulator, comparing between single connection, static PD and PD with the proposed prediction model. The evaluation results show that the prediction model reduced the number of packets sent with PD by 81% while maintaining the same level of latency as a static PD technique, which derives from a more efficient usage of the network resources.

Luminescent 2-phenylbenzothiazole cyclometalated PtII and IrIII complexes with chelating P

Two series of cyclometalated PtII and IrIII complexes with general formulas [Pt(pbt){PPh2(R)-κP,O}] (2a-2c) and [Ir(pbt)2{PPh2(R)-κP,O}] (3a-3c), where Hpbt is 2-phenylbenzothiazol and PPh2(R) is a diphenylphosphino donor functionalized deprotonated acid (R = o-C6H4CO2a, o-C6H4SO3b, CH2CH2CO2c) are presented. The structures of 1, 2a-2c, 3a and 3b were confirmed by single X-ray diffraction analyses, and the intermolecular interactions in 2a were studied using Hirshfeld surface analysis and non-covalent interaction (NCI) methods on its X-ray structure. Their photophysical properties were investigated by absorption and emission analyses [CH2Cl2, solid (298, 77 K) and doped polystyrene (PS) films], supported by TD-DFT calculations on 1, 2a-2c and 3a. The PtII complexes exhibit bright phosphorescence in the region 525-542 nm, ascribed to a mixed 3IL/3MLCT excited state with a predominant 3IL contribution. The IrIII derivatives (3a-3c) show orange photoluminescence (535-584 nm, 298 K), blue shifted at 77 K (527-560 nm), originated from the admixture of 3IL/3MLCT/3LLCT excited states. Interestingly, the photoluminescence quantum yields of the Pt complexes 2a-2c (ϕ = 46.5-66.5%) in PS films are remarkably higher than those of the corresponding iridium complexes (ϕ = 17.3-32%) and the precursor 1 (ϕ = 17%). The calculated 3MC-3IL/3MLCT energy gap for 2a and 3a accounts for the higher quantum yield of the Pt in relation to the Ir complex.

5G Numerologies Assessment for URLLC in Industrial Communications.

The fifth-generation (5G) network is presented as one of the main options for Industry 4.0 connectivity. Ultra-Reliable and Low Latency Communications (URLLC) is the 5G service category used by critical mechanisms, with a millisecond end-to-end delay and reduced probability of failure. 5G defines new numerologies, together with mini-slots for a faster scheduling. The main challenge of this is to select the appropriate numerology according to radio conditions. This fact is very important in industrial scenarios, where the fundamental problems are interference and multipath propagation, due to the presence of concrete walls and large metallic machinery and structures. Therefore, this paper is focused on analyzing the impact of the numerology selection on the delay experienced at radio link level for a remote-control service. The study, which has been carried out in a simulated cellular factory environment, has been performed for different packet sizes and channel conditions, focusing on outliers. Evaluation results show that not always a higher numerology, with a shorter slot duration, is appropriate for this type of service, particularly under Non-Line-of-Sight (NLOS) conditions.

Pseudohemorragia subaracnoidea. Presentación de un caso / Pseudo-subarachnoid Hemorrhage. A Case Report

La pseudohemorragia subaracnoidea es un fenómeno infrecuente que se caracteriza por hallazgos sugestivos de hemorragia subaracnoidea en la tomografía computarizada simple de cráneo, sin evidencia de la misma en estudios adicionales. Se ha asociado a múltiples causas, de las cuales la principal es la encefalopatía hipóxico-isquémica posparo cardiaco y reanimación cardiopulmonar. El contexto clínico y los niveles de atenuación medidos en Unidades Hounsfield (UH) se deben tener en cuenta al hacer el diagnóstico diferencial entre ambas entidades. Se presenta el caso de una paciente con pseudohemorragia subaracnoidea de etiología multifactorial.

Pseudo-subarachnoid hemorrhage (PSAH) is an infrequent entity characterized by findings in non- contrast head computed tomography that mimic subarachnoid hemorrhage, but without evidence of blood products in further studies. It has been associated with multiple etiologies, with hypoxic ischemic encephalopathy following cardiac arrest and cardiopulmonary resuscitation as the leading cause in literature. Clinical context and attenuation levels measured in Hounsfield Units should be taken into consideration when establishing the differential diagnosis between these entities. The case of a patient with PSAH of multifactorial etiology is presented.

Adherencia al tratamiento antirretrovirales en pacientes del CAI, del Hospital Regional "Gabriela Alvarado", Danlí, El Paraíso, Honduras. Enero - Mayo 2013

El VIH/SIDA sigue siendo uno de los más graves problemas de salud pública delmundo, especialmente en los países de ingresos bajos o medios.Centroamérica es la sub-región más afectada, después del Caribe, por la epidemiade VIH/SIDA en la región de Latino América y el Caribe. Cuatro de los seis paísesde América Latina con mayores tasas de prevalencia de infección por VIH estánen Centroamérica, y en tres de ellos las tasas de prevalencia son superiores oiguales al 1% (con el 2,5% en Belice, con el 1,6 % en Honduras y el 0,9% enGuatemala).Ante la alta incidencia del VIH en nuestro país, así como la aplicación detratamientos antirretrovirales, en el Centro de Atención Integral (CAI); del HospitalRegional Gabriela Alvarado de la Ciudad de Danlí, El Paraíso; nos vemosmotivados a indagar cual es el producto de los mismos.

Dengue en la ciudad de El Paraíso, departamento de El Paraíso, Honduras: segundo semestre de 2010 / Dengue in the city of El Paraíso department of El Paraiso, Honduras: second semester, 2010

Estudio descriptivo con método cuantitativo. Se encontró que la baja escolaridad, el poco ingreso económico entre otros, se convierten en factores determinantes para la propagación de enfermedades como el Dengue debido a las condiciones de las viviendas, barrios y las condiciones y estilos de vida de los habitantes