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Understanding the factors governing the self-assembly of organic ligands with metal ions is essential to engineering target molecular arrangements with the desired properties. Indeed, small modifications of the synthetic conditions lead to the obtention of different complexes, varying from discrete monomers to coordination polymers (CPs). Based on the potential coordinating ability of 2-furoic acid (2-FA), we prepared five Zn(II) and Cd(II) complexes to study the behavior of the furane O atom and the competitiveness of the M-O bond formation in methanol (MeOH). Reactions between M(OAc)2·2H2O (M = Zn(II), Cd(II)), 2-FA, and two p-substituted pyridine ligands (isonicotinamide (Isn) and 4-acetylpyridine (4-Acpy)) in MeOH yielded the two dimers [Zn(μ-2-FA)(2-FA)(Isn)2]2 (1) and [Cd(μ-2-FA)(2-FA)(Isn)2]2 (2), the dimeric paddle-wheel [Zn(μ-2-FA)2(4-Acpy)]2 (3), and the monomer [Cd(2-FA)2(4-Acpy)2(OH2)] (4). Their crystal structures have been studied, observing diverse coordination numbers between five and seven and diverse coordination modes of the carboxylate groups. Interestingly, the recrystallization of 4 in acetonitrile (ACN) resulted in a dissolution-recrystallization structural transformation (DRST), leading to an intricate coordination polymer (CP) with the formula {[Cd(μ-2-FA)(2-FA)(OH2)2]n[Cd(μ-2-FA)(2-FA)(4-Acpy)(OH2)]n} (5) exhibiting coordination of the furane O atom. Within this collection of arrangements, 2-FA displayed a great diversity of coordination modes that were combined and interchanged in the DRST process. Their photophysical properties in solution have been analyzed and their quantum yields calculated. Likewise, further insight into the DRST process was obtained from fluorescence measurements. From these results, a pathway for the structural transformation highlighting the crucial role of solvents has been proposed.

Altres ajuts: acords transformatius de la UAB Altres ajuts: J.P. acknowledges financial support from the CB615921 project, the CB616406 project from "Fundació La Caixa". D.E. acknowledges the PIF predoctoral fellowship from the Universitat Autònoma de Barcelona. The behavior of coordination polymers (CPs) against external stimuli has witnessed remarkable attention, especially when the resulting CPs present reversible molecular arrays. Accordingly, CPs with these characteristics can lead to differences in their properties owing to these structural differences, being promising for their use as potential molecular switches with diverse applications. Herein, we have synthesized four Zn(II) CPs bearing α-acetamidocinnamic acid (HACA) and 4,4'-bipyridine (4,4'-bipy). The reaction between Zn(OAc)2·2H2O, HACA, and 4,4'-bipy yields {[Zn(ACA)2(4,4'-bipy)]·EtOH}n (1), which was used for the formation of three CPs through dissolution-recrystallization structural transformations (DRSTs): {[Zn(ACA)2(4,4'-bipy)]·2MeOH}n (2), {[Zn2(μ-ACA)2(ACA)2(4,4'-bipy)]·2H2O}n (3), and {[Zn3(μ-ACA)6(4,4'-bipy)]·0.75CHCl3}n (4). The study of the four crystal structures revealed that their secondary building units (SBUs) comprise monomeric, dimeric, and trimeric arrangements linked by 4,4'-bipy ligands. The fundamental role of the utilized solvent and/or temperature, as well as their effect on the orientation of the amide moieties driving the formation of the different SBUs is discussed. Furthermore, the reversibility and interconversion between the four CPs have been assayed. Finally, their solid-state photoluminescence has evinced that the effect of the amide moieties not only predetermine a different SBU but also lead to a different emission in 4 compared with 1-3.

Five Cd(ii) complexes based on α-acetamidocinnamic acid (HACA) and a set of N,N^N and N^N^N-pyridine (dPy) yield complexes with diverse nuclearities and enhanced quantum yields, benefiting from the chelation enhanced effect (CHEF) of dPy.

Comproportionation between Hg0 and Hg2+ resulted in the formation of [Hg2(Pip)2] supported by Hg⋯Odioxole and Hg⋯π interactions. Structural and computational assessment determined the tendency of Hg(i) to partake in Hg⋯π interactions.

Hoping to highlight the flexibility of a bispyrazole ligand possessing an ether chain including a weak spot (1,2-bis([4-(3,5- dimethyl -1 H - pyrazol -1- yl )-2- oxabutyl ]benzene ( L )), its reactivity against coordinatively flexible metal centres has been assayed. Thus Co(II) and Cu(II) coordination complexes of L have been synthesized and fully characterized by analytical and spectroscopical methods. Their X-ray crystal struc- ture elucidation has allowed to ascertain that while the Co(II) compound {[C o ( L )C l 2 ] ·1/2H 2 O} n ( 1 ) pos- sesses a polymeric structure, much like its Zn(II), Cd(II) and Hg(II) analogues, the Cu(II) compound [Cu 2 L Cl 4 ] ( 2 ) displays a completely unexpected dimeric architecture. The previously unreported coordi- nation mode of the ligand in the Cu(II) compound causes dramatical changes in the morphology of the resulting complexes. Their crystal structures are discussed in deep, and the causes behind their differing architectures are examined through comparison with bibliographical references, La Caixa Foundation CB615921 CB616406, Generalitat de Catalunya 2017/SGR/1687, Universitat Autonoma de Barcelona

Altres ajuts: acords transformatius de la UAB Altres ajuts: Fundació La Caixa (projectes CB615921 i CB616406) The understanding of the effect generated by small differences of the organic ligands on the molecular and supramolecular arrangement of coordination polymers (CPs) is a key factor to control their properties. Therefore, the study of structurally related ligands differing in some factors inter alia functional group orientation, length, or functionality is a crucial task for crystal engineers. In this contribution, the reactions between Cd(OAc)2·2H2O, α-acetamidocinnamic acid (HACA) and different N,N-donor spacers with increasing length (pyrazine, pyz; 4,4'-bipyridine, 4,4'-bipy; 1,2-bis(4-pyridyl)ethylene, 1,2-bpe), as well as additional functionalities (4,4'-azopyridine, 4,4'-azpy) have been successfully performed. Their crystal structures have been elucidated revealing a family of ladder-type 1D CPs showing molecular arrays with single pillars for {[Cd2(μ-ACA)2(ACA)2(pyz)(H2O)2]·2EtOH}n (1), and double pillars for [Cd2(μ-ACA)2(ACA)2(4,4'-bipy)2]n (2), [Cd2(μ-ACA)2(ACA)2(1,2-bpe)2]n (3) and {[Cd2(μ-ACA)2(ACA)2(4,4'-azpy)2]·4,4'-azpy·9H2O}n (4). Remarkably, the effect of the addition of the azo group in 4 compared with 2 and 3 has led to a CP with the same molecular arrangement but different crystal packing, allowing the introduction of one non-coordinated 4,4'-azpy and nine water molecules. Finally, their solid-state UV-Vis and photoluminescence have been measured observing their blue-emitting properties.

Polymorphic crystallization of cocoa butter (CB) in a bulk system was examined for the influence of adding talc particles at different concentrations (0.1%-5%). While the system was cooled from the melt and subsequently heated, changes in the heat flow and crystal structure of CB were analyzed using differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (SR-XRD). Synchrotron radiation microbeam X-ray diffraction (SR-µ-XRD) was employed to determine lamellar-plane directions of CB crystals occurring with talc addition. At any cooling rates (0.1-15 °C/min) applied, talc promoted CB crystallization to elevate the onset crystallization temperature logarithmically with the increasing concentration of talc; this effect became more prominent at higher cooling rates. Talc also acted as a polymorphic stabilizer, so that CB crystallized in more stable forms even when cooled at the highest rate of 15 °C/min. Moreover, a highly ordered lamellar-plane direction was extensively observed for CB crystals occurring with 0.1% talc addition, which was disturbed by 0.5% talc addition probably due to the spatial dispersion of densely populated talc particles in their randomized orientation. These heterogeneous nucleation effects indicate the potential of talc particles to be used for quality and productivity control of CB-based products.

Simetría es equivalencia, proporción, armonía e incluso belleza. La simetría está implícita en los cristales, y por lo tanto en los minerales, como una propiedad derivada de la periodicidad. Nos ayuda en la comprensión y descripción de la materia cristalina, tanto a escala macroscópica como microscópica. Pero simetría es un concepto interdisciplinar por excelencia que utilizamos en química, física, matemáticas, zoología, botánica, y también en la música, la pintura, la ornamentación, la arquitectura…A un nivel de divulgación científica desarrollaremos algunos conceptos fundamentales de la simetría y los aplicaremos en diferentes dominios de nuestro entorno cotidiano.

Arbequina monovarietal extra virgin olive oil (EVOO) was fractionated through a multi-step dry fractionation method. Three of the isolated fractions were selected and analyzed: one being liquid at 4 °C, and two being solid at 4 °C, and at 12 °C. Differential scanning calorimetry (DSC) combined with synchrotron radiation X-ray diffraction (SR-XRD) techniques were employed to monitor the polymorphic crystallization and transformation processes when samples were cooled from the melt to complete crystallization and reheated at a rate of 2 °C/min. Fatty acid profiles and α-tocopherol contents were also determined for EVOO and associated fractions. Each sample exhibited a different and unique crystallization and polymorphic behavior, and the number of crystallizing forms and complexity of transitions increased for solid fractions. In more detail, just two polymorphs (β'3- 2L and β'2-2L) were detected in the liquid fraction, whereas the fraction which remained in the solid state at 12 °C exhibited six different phases (α-2L; β'3-2L; β'2-2L; β'1-2L; β'2-3L; β'1-3L). These dissimilarities were strongly correlated with meaningful variations in the fatty acid moieties forming TAG structures and caused large deviations in the crystallization and melting temperatures. As an example, melting temperatures of the liquid and the solid fraction at 12 °C were about -3 °C and 17 °C, respectively. It may be worth exploring the potential of EVOO fractions to be used for improving properties of food stuff, among others. The liquid fraction may be of interest due to its high nutritional value owing to elevated contents in monounsaturated fats and antioxidants, whereas the solid fraction at 12 °C may become a good choice to be used as a high-oleic soft fat.

The isolation and structural characterization of a unique Cu(II) isonicotinate (ina) material with 4-acetylpyridine (4-acpy) is provided. The formation of [Cu(ina)2(4-acpy)]n (1) is triggered by the Cu(II) aerobic oxidation of 4-acpy using O2. This gradual formation of ina led to its restrained incorporation and hindered the full displacement of 4-acpy. As a result, 1 is the first example of a 2D layer assembled by an ina ligand capped by a monodentate pyridine ligand. The Cu(II)-mediated aerobic oxidation with O2 was previously demonstrated for aryl methyl ketones, but we extend the applicability of this methodology to heteroaromatic rings, which has not been tested so far. The formation of ina has been identified by 1H NMR, thus demonstrating the feasible but strained formation of ina from 4-acpy in the mild conditions from which 1 was obtained.

Differential scanning calorimetry and X-ray diffraction were used to investigate the mixing behavior of triacylglycerol (TAG) mixtures of PPP/PPO (tripalmitoyl glycerol/1,2-dipalmitoyl-3-oleoyl-rac-glycerol) and PPP/MCPOP/PPO (where MCPOP/PPO is the equimolecular blend of 1,3-dipalmitoyl-2-oleoyl-glycerol and PPO forming a molecular compound) under metastable and stable conditions. During cooling and reheating treatments at moderate rates, the eutectic properties of the two systems examined were mainly governed by the crystallization, transformation, and melting behavior of structurally similar β′ forms. In addition, steric and kinetic effects determined the formation of solid solutions with up to 10% and 20% of mixed-acid components in PPP/PPO and PPP/MCPOP/PPO mixtures, respectively. These values increased to 30% and 35% when thermodynamically stable β crystalline phases were obtained. In PPP/MCPOP/PPO mixtures, the diffraction data suggested that POP and PPO acted as a single component by dissolving in similar amounts in the solid solution phases and forming molecular compound crystals in eutectic compositions. This fundamental research shows the important role of specific combinations of mixed-acid TAGs and their interaction with high-melting components on the solidification behavior of edible lipids.

The coordination behaviour of two N,O-hybrid hydroxyethylpyrazole ligands, 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethanol, HL1; and (2-(3,5-di(2-pyridyl)-1H-pyrazol-1-yl)ethanol, HL2; with CuCl2·2H2O and Cu(NO3)2·3H2O were studied. Four copper complexes: [CuCl(µ-L1)]2·HL1 (1), [CuCl2(HL2)]·H2O (2A), [Cu(NO3)(3,5-hdppz)(µ-L1)]2·2CH3CN (3), (3,5-hdppz = 3,5-diphenylpyrazole) and [Cu(H2O)(3,5-dpypz)]2(NO3)2·H2O (4), (3,5-dpypz = 3,5-(2-pyridyl)pyrazolate) were isolated and characterized by analytical methods and spectroscopical studies. From their crystal structure, a Npz-C bond cleavage was observed for HL1 and HL2 upon reaction with Cu(NO3)2·3H2O, yielding the unexpected complexes 3 and 4, respectively. Overall, these complexes provided great structural diversity, as dimers (asymmetric and symmetric), monomers and ionic complexes were obtained. Finally, magnetic susceptibility measurements for 3 were carried out, showing the dependence of the magnetic moment on Cu-O-Cu angles., J.P. thanks CB615921 project, the CB616406 project from “Fundació La Caixa” and the Generalitat de Catalunya (2017/SGR/1687). T.C. thanks the Spanish National Plan of Research MAT2015-65756R. J.G.P. thanks MINECO (PID2019-106832RB-I00), MICINN through the Severo Ochoa Program for Centers of Excellence for the FUNFUTURE (CEX2019-000917-S and MDM-2017-0767 projects) and the Generalitat de Catalunya (2017/SGR/1720 and SGR2017-1289). J.S. also acknowledges the PIF pre-doctoral Fellowship from the Universitat Autònoma de Barcelona for his pre-doctoral grant., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

Altres ajuts: acords transformatius de la UAB Altres ajuts: J.P. acknowledges financial support from the CB615921 project, the CB616406 project from "Fundació La Caixa" Controlling the formation of the desired product in the appropriate crystalline form is the fundamental breakthrough of crystal engineering. On that basis, the preferential formation between polymorphic forms, which are referred to as different assemblies achieved by changing the disposition or arrangement of the forming units within the crystalline structure, is one of the most challenging topics still to be understood. Herein, we have observed the formation of two concomitant polymorphs with general formula {[Hg(Pip)2(4,4'-bipy)]·DMF}n (P1A, P1B; Pip = piperonylic acid; 4,4'-bipy = 4,4'-bipyridine). Besides, [Hg(Pip)2(4,4'-bipy)]n (2) has been achieved during the attempts to isolate these polymorphs. The selective synthesis of P1A and P1B has been successfully achieved by changing the synthetic conditions. The formation of each polymorphic form has been ensured by unit cell measurements and decomposition temperature. The elucidation of their crystal structure revealed P1A and P1B as polymorphs, which originates from the Hg(II) cores and intermolecular associations, especially pinpointed by Hg···π and π···π interactions. Density functional theory (DFT) calculations suggest that P1B, which shows Hg(II) geometries that are further from ideality, is more stable than P1A by 13 kJ·mol-1 per [Hg(Pip)2(4,4'-bipy)]·DMF formula unit, and this larger stability of P1B arises mainly from metal···π and π···π interactions between chains. As a result, these structural modifications lead to significant variations of their solid-state photoluminescence.

The training received during primary and secondary education is crucial for the development of our behavior in adulthood. For this reason, at this early stage, it is important to know our environment and its dynamics to appreciate it. The Spanish Secondary Compulsory Education (SCE) comprises four academic years and is taken by students aged 12-16. The learning of geosciences during this level takes place only in the first, third and fourth year. Biology and geology are part of the same subject, being mandatory in the first and third year and optional in the last year. The students lose their interest in science as they advance from primary to secondary education and cease to see it as a viable option for their future (Zamalloa and Sanz, 2020). Several authors have also detected this lack of interest in science of young people (Ali et al., 2013; Christidou, 2011). This disinterest is manifested in expressions such as "Science does not provide food", "You have to study hard" or "Science is boring". To avoid this lack of motivation, educational models should be reoriented towards an educational system in which students are at the center of their learning and not simply focused on the systematic acquisition of memorized concepts to pass an exam. The discipline of Earth Sciences, or Geosciences, face a more difficult challenge than many other sciences given that students do not learn geology during early stages of their academic life (Adetunji et al., 2012). In many places such as the USA (Lewis, 2008), Australia (Dawborn-Gundlach et al., 2017), some countries of northern Europe (King, 2013), Argentina and other Latin American countries (Lacreu 2017; UNESCO, 2019) and Spain (Pedrinaci, 2012) geoscience subjects are underrepresented and frequently in the optional subjects, it is selected by students who are unmotivated. Given this context, the present study investigates the structure of geoscience education in the frame of the SCE system from Catalonia and the degree of geological knowledge acquired by the students.

Three different paddle wheel compounds have been synthesized, each one via a different synthetic pathway. The first method is the reaction of Cu(MeCO2)2·H2O with 1,3-benzodioxole-5-carboxylic acid (Piperonylic acid, HPip) in a MeOH solution, yielding [Cu(µ-Pip)2(MeOH)]2 (1). The second method is the transformation of the heteroleptic core paddle-wheel compound [Cu(µ-MeCO2)(µ-Pip)(MeOH)]2 into the homoleptic core paddle-wheel [Cu(µ-Pip)2(DMSO)]2·2DMSO (2). Lastly, the third method is the substitution of the solvent molecule (DMF) present in the molecular array [Cu(µ-Pip)2(DMF)]2 by 2-benzylpyridine (2-Bzpy) ligand, resulting in [Cu(µ-Pip)2(2-Bzpy)]2·2.5MeOH·H2O (3a). All compounds are characterized via EA, PXRD, ATR-FTIR, Far-IR and UV–Vis spectroscopy. For all three compounds, the X-ray crystal structure has been determined and their extended structures are discussed. Finally, TG/DTA measurements have been recorded.

Since many factors influence the coordination around a metal center, steric and electronic effects of the ligands mainly determine the connectivity and, thus, the final arrangement. This is emphasized on Hg(II) centers, which have a zero point stabilization energy and, thus, a flexible coordination environment. Therefore, the unrestricted Hg(II) geometry facilitates the predominance of the ligands during the structural inception. Herein, we synthesized and characterized a series of six Hg(II) complexes with general formula (Hg(Pip)2(dPy)) (Pip = piperonylate, dPy = 3-phenylpyridine (3-phpy) (1), 4-phenylpyridine (4-phpy) (2), 2,2′-bipyridine (2,2′-bipy) (3), 1,10-phenanthroline (1,10-phen) (4), 2,2′:6′,2′-terpyridine (terpy) (5), or di(2-picolyl)amine (dpa) (6)). The elucidation of their crystal structures revealed the arrangement of three monomers (3, 5, and 6), one dimer (4), and two coordination polymers (1 and 2) depending on the steric requirements of the dPy and predominance of the ligands. Besides, the study of their photophysical properties in solution supported by TD-DFT calculations enabled us to understand their electronic effects and the influence of the structural arrangement on them., Six Hg(II) complexes containing 1,3-benzodioxole-5-carboxylic acid and pyridine derivatives bearing N-, N^N′-, and N^N^N-donor sites have been characterized and their crystal structure elucidated. Steric crowding defined the predominance of the linkers in the structural arrangement, varying from monomers to coordination polymers. Their photophysical properties were analyzed through experimental and TD-DFT calculations, identifying the character and regions involved on each electronic transition. In addition, seclusion of the HOMO from the LUMO defined them as appropriate to selective band gap tuning.

Altres ajuts: Fundació La Caixa: CB615921; CB616406; UAB: programa de beques PIF predoctorals The reactions of piperonylic acid (HPip) and cinnamic acid (HCinn) with 4,4'-bipyridine (4,4'-bipy) have been assayed using the same synthetic methodology, yielding two binary cocrystals with different acid:4,4'-bipy molar ratios, (HPip)(4,4'-bipy) (1) and (HCinn)2(4,4'-bipy) (2). The melting point (m.p.) of these cocrystals have been measured and a remarkable difference (ΔT ≈ 78 °C) between them was observed. Moreover, the two cocrystals have been characterized by powder X-ray diffraction (PXRD), elemental analysis (EA), FTIR-ATR, 1H NMR spectroscopies, and single-crystal X-ray diffraction. The study of their structural packings via Hirshfeld surface analysis and energy frameworks revealed the important contribution of the π···π and C-H···π interactions to the formation of different structural packing motifs, this being the main reason for the difference of m.p. between them. Moreover, it has been observed that 1 and 2 presented the same packing motifs as the crystal structure of their corresponding carboxylic acids, but 1 and 2 showed lower m.p. than those of the carboxylic acids, which could be related to the lower strength of the acid-pyridine heterosynthons respect to the acid-acid homosynthons in the crystal structures.

The binary phase behavior of triacylglycerol (TAG) mixtures constituted by PPP (tripalmitin) and either POP (1,3-dipalmitoyl-2-oleoyl-glycerol), OPO (1,3-dioleoyl-2-palmitoyl-glycerol), or MCPOP/OPO (molecular compound formed by POP/OPO at a 1:1 concentration ratio) was determined by differential scanning calorimetry (DSC), synchrotron (SR-) and laboratory-scale X-ray diffraction (XRD). Steric hindrance due to saturated-unsaturated acyl chain interactions and differences in the thermal stability of TAGs seemed to dictate the independent polymorphic crystallization and transformation observed under kinetic conditions, as well as the very asymmetric eutectic-type phase diagrams obtained from the study of thermodynamically stabilized PPP/POP, PPP/OPO, and PPP/MCPOP/OPO mixtures. Moreover, the solid integration determined for MCPOP/OPO in the βPPP crystalline phase (20-25%), halfway between that of OPO (

The coordination behaviour of N,O-hybrid pyrazole ligand 2-(3,5-dimethyl-1H-pyrazol-1-yl)ethanol (HL) against different Cu(II) salts has been studied. Five coordination complexes (1–5) have been synthesized and characterized by elemental analysis, conductivity measurements and spectroscopic measurements. Moreover, the crystal structure of all five compounds has been elucidated, allowing the detailed study of their molecular and supramolecular structure. The obtained compounds are structurally diverse, as ionic monomers, neutral dimers and a polymer have been isolated. Their nuclearity seems to be very dependent on the deprotonation of the pyrazole moiety, whereas co-ligands have a direct influence on their dimensionality and supramolecular structure. Upon crystallization, compound 5 adsorbs water molecules, resulting in a particularly intriguing supramolecular network. In this scaffold, the presence of three water moieties playing different supramolecular roles has been analysed via computational methods and thermogravimetric analyses. Lastly, magnetic susceptibility measurements have been carried out for 3 and 5 and the results were rationalized on account of their structure.

The synthesis and characterization of one coordination polymer and two trinuclear complexes are presented. The coordination polymer [Zn2(&micro, O,O&rsquo, ACA)2(ACA)2(4-Phpy)2]n (1) has been obtained by the reaction between Zn(OAc)2&middot, 2H2O, &alpha, acetamidocinnamic acid (HACA), and 4-phenylpyridine (4-Phpy) using EtOH as solvent. Its recrystallization in CH3CN or EtOH yields two trinuclear complexes, both having pinwheel arrays with formulas [Zn3(&micro, ACA)6(4-Phpy)2]&middot, 4CH3CN (2&middot, 4CH3CN) and [Zn3(&micro, ACA)6(EtOH)2]&middot, 4EtOH (3&middot, 4EtOH), respectively. These trinuclear species, unavoidably lose their solvent co-crystallized molecules at RT yielding the complexes [Zn3(&micro, ACA)6(4-Phpy)2] (2) and [Zn3(&micro, ACA)6(EtOH)2] (3). In addition, compound 2 has also been obtained reacting Zn(OAc)2&middot, 2H2O, HACA, and 4-Phpy in a 1:2:2 ratio using CH3CN as solvent. Compounds 1&ndash, 3 have been characterized by analytical and spectroscopic techniques. Furthermore, single crystals suitable for X-ray diffraction method for compounds 1, 2&middot, 4CH3CN, and 3&middot, 4EtOH were obtained and their supramolecular interactions have been studied and discussed, showing 2D supramolecular planes for the trinuclear complexes and a 3D supramolecular network for the coordination polymer. Finally, the supramolecular interactions of 2&middot, 4CH3CN and 3&middot, 4EtOH have been compared using Hirshfeld surface analysis and electrostatic potential calculations.

High-commercial-value products are often susceptible to food fraud. Among them, Iberian dry-cured ham is highly appreciated due to its particular and sensory, but also nutritional, properties. There are four different Iberian ham categories (namely bellota, recebo, cebo de campo and cebo), which directly depend on the rearing system of the pig during the last stage of the fattening phase. However, there is still a lack of a normalized and robust method capable of authenticating the different product categories and, therefore, preventing mislabeling. In the present work, we characterized the polymorphic behavior of raw (before curing) lipid extracts belonging to the four categories of Iberian pig. A total of 80 different samples were analyzed by DSC, and synchrotron radiation XRD experiments were carried out for selected ones. The results obtained showed that bellota and recebo categories exhibited essentially the same crystallization and polymorphic behavior and this was significantly different (p

The crystallization properties of triacylglycerols (TAGs) strongly determine the functional properties of natural lipids. The polymorphic and mixing phase behavior of TAG molecules have long been, and still are, a hot topic of research with special relevance for the cosmetic, pharmaceutical, and food industry. To avoid the difficulties arising from the study of whole real fats, studies at the molecular level on mixtures of a limited number of TAGs has become an indispensable tool to identify the underlying causes of the physical properties in lipid systems. In particular, phase diagrams of binary mixtures of TAGs exhibiting a different degree of heterogeneity (monoacid or mixed fatty acids; molecular symmetry; the presence of cis or trans double bonds) have resulted in a significant breakthrough in our knowledge about structure–interaction–function relationships. The present work aims to provide an overview of the main reports regarding binary and ternary TAG systems, from the early studies to the most recent developments.

Four new compounds, formulated as [Zn(m-Pip)2(3-Phpy)]2 (1), [Zn(m-Pip)2(4-Phpy)]2 (2), [Cd(m-Pip)(Pip)(3-Phpy)2]2 (3) and [Cd(m-Pip)(Pip)(4-Phpy)2]2 (4) (HPip=1,3-benzodioxole-5-carboxylic acid; Phpy= phenylpyridine), have been successfully assembled based on rigid carboxylate/pyridine ligands. These four compounds have been fully characterized by analytical and spectroscopic methods. The aim of the present study is to investigate the structural effect and the influence of the size of metal on the class, geometry and type of coordination of the carboxylate ligands (syn-syn, syn-anti) in the final 3D-arrangements of the structures. Finally, luminescence properties of these new four coordination dimers have been investigated.

The study of the cycloplatination of the ferrocenyl-pyrazole [1-{MeO(CH2)2}-3,5-Ph2-4-(CH2Fc)-(C3N2)] (1) has allowed us to isolate and characterize the trimetallic compound [Pt{(κ2-C,N)[1-[MeO(CH2)2]-3-(C6H4)-5-Ph-4-(CH2Fc)-(C3N2)]}(1)Cl] (3) that contains two units of ligand 1 adopting two different binding modes. Further studies of the reactivity of compound 3 with PPh3 in the absence or in the presence of AgNO3 gave the heterodimetallic complexes [Pt{(κ2-C,N)[1-[MeO(CH2)2]-3-(C6H4)-5-Ph-4-(CH2Fc)-(C3N2)]}(X)(PPh3)] [X = Cl− (4) and NO2− (5)]. The X-ray crystal structures of 3·1/2CH2Cl2 and 5·CH2Cl2 confirmed: a) the existence of heterotri- (in 3) or dimetallic molecules (in 5), b) the mode of binding of ligand 1, and c) the presence of N-bonded NO2− ligand (in 5). Comparative studies of the cytotoxic activity of the new products in the MCF7 and MDA-MB-231 (breast) and in the cisplatin resistant HCT116 (colon) cancer cell lines reveal that the potency of the metallacycles depends on the nature of the ancillary ligands (X and L) and increases according to the sequence 3 (L = 1 and X = Cl−) «5 (L = PPh3 and X = NO2−)

The study of the reactivity of three 2-phenyl-3H-indole ligands of general formulae C8H3N-2-(C6H4-4-R1)-3-NOMe-5-R2 (1) [with R1 = H, R2 = OMe (a), R1 = R2 = H (b) or R1 = Cl, R2 = H (c)] with [Pd(&eta, 3-1-R3C3H4)(&mu, Cl)]2 (R3 = H or Ph) has allowed us to isolate two sets of new Pd(II)-allyl complexes of general formulae [Pd(&eta, 3-1-R3C3H4)(1)Cl] {R3 = H (2) or Ph (3)}. Compounds 2a&ndash, 2c and 3a&ndash, 3c were characterized by elemental analyses, mass spectrometry and IR spectroscopy. The crystal structures of 2a, 3a and 3b were also determined by X-ray diffraction. 1H-NMR studies reveal the coexistence of two (for 2a&ndash, 2c) or three (for 3a&ndash, 3c) isomeric forms in CD2Cl2 solutions at 182 K. Additional studies on the catalytic activity of mixtures containing [Pd(&eta, 3-C3H5)(&mu, Cl)]2 and the parent ligand (1a&ndash, 1c) in the allylic alkylation of (E)-3-phenyl-2-propenyl (cinnamyl) acetate with sodium diethyl 2-methylmalonate as well as the stoichiometric reaction between compounds 3a and 3c with the nucleophile reveal that in both cases the formation of the linear trans- derivative is strongly preferred over the branched product. Computational studies at a DFT level on compound 3a allowed us to compare the relative stability of their isomeric forms present in solution and to explain the regioselectivity of the catalytic and stoichiometric processes.

The compound [Cu(µ-Pip)(µ-OAc)(MeOH)]2 (1) (Pip = Piperonylate, OAc = acetate, MeOH = methanol) has been obtained in high percentage yield. Its reactivity with pyridine/pyrazole derivative ligands (pyridine (py), 3-phenylpyridine (3-Phpy) and 4-acetylpyridine (4-Acpy)) and 3,5-dimethylpyrazole (3,5-dmpz) leads to four monomeric compounds: [Cu(Pip)2(dPy)2(H2O)] (dPy = py (2), 3-Phpy (3) and 4-Acpy (4a)) and [Cu(Pip)2(3,5-dmpz)2] (5). Furthermore, the reaction of 1 with HPip in MeOH:DMF solvent under reflux conditions yields the homoleptic core paddle-wheel compound [Cu(µ-Pip)2(DMF)]2·2DMF (6). The reaction between 6 and 2-benzylpyridine (2-Bzpy) yields the paddle-wheel core compound [Cu(Pip)2(2-Bzpy)]2 (7). All compounds have been fully characterized by analytical and spectroscopic techniques and their X-ray crystal structures have been determined. In this set of compounds, the carboxylate ligand (Pip) displays different coordination modes (monodentate (2–4), bidentate chelate (5) and bridged (1, 6 and 7)). Moreover, their extended structures are discussed: the crystal packing indicates hydrogen bond propagation, which defines 1D (2–5) or 2D (6 and 7) supramolecular networks., This work was financed by the Spanish National Plan of Research MAT2015-65756-R, CTQ2016-75150-R and 2017SGR1687, 2014SGR149 projects from the Generalitat de Catalunya for its financial support.

Reaction of M(MeCO2)2 (M = Zn(II), Cd(II), and Hg(II)) with 1,3-benzodioxole-5-carboxylic acid (HPip) in methanol (MeOH) yields four piperonylate compounds, one of Zn(II) ([Zn(Pip)2(H2O)2] (1c)), two of Cd(II) ([Cd(μ-Pip)2(H2O)]n (2) and [Cd3(μ-Pip)6(MeOH)2]n (3)), and one of Hg(II) ([Hg(μ-Pip)2]n (4)). The obtention of compounds 1c and 4 was independent of the M/L ratio. These four compounds were characterized by analytical and spectroscopic techniques. In addition, the thermal stability of 1c, 2, and 4 has been studied, and the structure of all the complexes has been determined by the single crystal X-ray diffraction method. The Zn(II) compound displayed a monomeric structure, while Cd(II) and Hg(II) complexes exhibited three polymeric arrays. The Zn(II) (1c) and Hg(II) (4) centers are four- and eight-coordinated in a tetrahedral or squareantiprism geometry, respectively. Furthermore, the Cd(II) ions are either six- (2) or six- and seven- (3) coordinated in a octahedral or both octahedral and pentagonal bipyramid geometries, respectively. In these compounds, the Pip ligand presents different coordination modes: μ1-η1 (1c); μ2-η1:η1 and μ2-η2:η1 (2); μ2-η1:η1, μ2-η2:η1 and μ3-η2:η1:η1 (3); μ1-η2 and μ2-η2:η1 (4). The extended structures were also analyzed. Their photoluminescence properties have been examined, and the quantum yields have been calculated.

The present study aims at observing the crystallization and polymorphic behavior of cocoa butter (CB) in fresh cacao beans with DSC and X-ray diffraction techniques. Underlying idea of this study was to relate the necessary conditions of germination of cacao beans to the crystallization of CB, which are present in oil-in-water emulsion droplets (lipid bodies) with diameters of 1-2 μm. Different cooling and heating conditions, with rates of 15, 2, 0.5, and 0.1 °C/min, were applied to fresh cacao beans and compared to bulk CB. The results showed that the crystallization temperatures (Tc) of CB in fresh cacao beans were lower than those of bulk CB at all the experimental conditions. In addition, polymorphic behavior of the occurrence of metastable and stable forms of CB was also different between the fresh cacao beans and the bulk state. The thermal behavior of fresh and dried cacao beans that have different geographical origins was also analyzed. This study indicates that the germination conditions of cacao beans are extended to low-temperature environmental areas by reducing the Tc value of CB in fresh beans than of the bulk oil. The results were consistent with the germination experiments of fresh cacao beans at different temperatures.

We examined the influence of dynamic thermal treatment (variation of cooling/heating rates) on the polymorphic crystallization and transformation pathways of 1-palmitoyl-2,3-dioleoyl glycerol (POO), 1-stearoyl-2,3-dioleoyl glycerol (SOO), and 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol (POL), which are major saturated-unsaturated-unsaturated (SUU) triacylglycerols (TAGs) of vegetable oils and animal fats (e.g., palm oil, olive oil, and Iberian ham fat). Using mainly a combination of differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (SR-XRD), we analyzed the polymorphic behavior of TAGs when high (15 °C min− 1), intermediate (2 °C min− 1), and low (0.5 °C min− 1) cooling and heating rates were applied. Multiple polymorphic forms were detected in POO, SOO, and POL (sub-α, α, β'2, and β'1). Transient disordered phases, defined as kinetic liquid crystal (KLC) phases, were determined in POO and SOO for the first time. The results demonstrated that more stable forms were directly obtained from the melt by decreasing the cooling rates, whereas less stable forms predominated at high cooling rates, as confirmed in our previous work. Regarding heating rate variation, we confirmed that the nature of the polymorphic transformations observed (solid-state, transformation through KLC phase, or melt-mediation) depended largely on the heating rate. These results were discussed considering the activation energies involved in each process and compared with previous studies on TAGs with different saturated-unsaturated structures (1,3-dioleoyl-2-palmitoylglycerol, 1,3-dipalmitoyl-2-oleoyl-glycerol, trioleoyl glycerol, and 1,2-dioleoyl-3-linoleoyl glycerol).

Foods with high added value, such as Iberian dry-cured products, are susceptible to fraud. Many attempts have been made to differentiate the commercial/quality categories of Iberian dry-cured hams by analytical determinations. However, as discrimination by such means is not fully reliable, legislation to prevent fraudulent practice is based on administrative controls and certification. Here, new analytical approaches based on ultrahigh resolution mass spectrometry (UHRMS) and crystallographic techniques applied to the lipid fraction, in combination with chemometrics, are studied. The results of the triacylglycerol profile determined by UHRMS and the fingerprint provided by the thermograms obtained by differential scanning calorimetry offer the promise of analytic discrimination of Iberian dry-cured ham categories. In addition, these determinations, in combination with chemometrics, may prove extremely useful to authenticate many foods containing high to moderate amounts of lipids.

Reaction of MO (MO = Metal oxide, M = Zn(II) or Cd(II)) with benzoic acid (HBz) in H2O/MeOH mixture as solvent yields two benzoate compounds: [Zn(µ-Bz)2]n (1) and [Cd(Bz)2(H2O)3] (2). In addition, the reaction between M(MeCO2)2 (M = Zn(II) or Cd(II)) with HBz and 4-acetylpyridine (4-Acpy) in a 1:2:4 M ratio and in MeOH solution, leads to the formation of [Zn(µ-Bz)2(4-Acpy)]2 (3) and [Cd(µ-Bz)2(4-Acpy)2]2 (4). These four compounds have been fully characterized by analytical and spectroscopic techniques. Besides, their crystal structures have been elucidated revealing a 1D coordination polymer (1), a monomer (2), a paddle-wheel (3) and a dimer (4). In 1, the Zn(II) ion is four-coordinated in a tetrahedral geometry while in 3 is penta-coordinated in a square-pyramidal geometry. By contrast, compounds 2 and 4 exhibit seven-coordinated Cd(II) ions in a pentagonal-bipyramidal geometry. In these set of compounds, the benzoate ligand presents different coordination modes such as bidentate bridged (µ2-η1:η1) (1 and 3), chelate (µ1-η2) (2) and both bridged and chelate (µ2-η2:η1) (4). Besides, their extended structures have been analyzed. Finally, the UV–Vis and fluorescence spectra of all the compounds have been recorded as well as their quantum yields calculated.

The reaction of copper(II) acetate monohydrate with p-hydroxycinnamic acid (HpOHcinn) and different pyridine derivatives (4-tert-butylpyridine, 4-tBupy; 4-acetylpyridine, 4-Acpy; 3-phenylpyridine, 3-Phpy; 4-phenylpyridine, 4-Phpy) was essayed in methanol solvent at room temperature. The crystal structures of the resulting compounds were elucidated. Their analysis shows that the choice of pyridine ligands determines different coordination modes of the pOHcinn ligand and the Cu(II) coordination, nuclearity and geometry. The pOHcinn acts as a monodentate carboxylate ligand in combination with 4-tBupy or 4-Phpy, yielding monomers and dimers, associated by hydrogen bonds into supramolecular networks in which the phenol group plays a key role. Conversely, in combination with 4-Acpy or 3-Phpy, the phenol group coordinates directly to the Cu(II), acting as a ditopic ligand and yielding 2D coordination polymers. The compound containing 3-Phpy shows interesting MeOH-H2O reversible exchange behavior. Not only has the pyridine auxiliary ligand had a tremendous effect on the coordination mode of pOHcinn, but also its reactivity is influenced. Particularly, in the case of the compound containing 4-Phpy, it undergoes a photoinduced process, in which the phenol group deprotonates and coordinates to Cu(II) as a phenoxy ligand. This yields a coordination polymer in which two different dimers alternate, bridged by the resulting pOcinn ligand. The magneto-structural correlation of this compound is also discussed.

[Cu(μ-MeCO2)2(4-Bzpy)]2 (4-Bzpy = 4-benzylpyridine) has been synthesized by reaction of [Cu(μ-MeCO2)2(H2O)]2 with 4-Bzpy in methanol at room temperature. The compound was characterized by Elemental Analysis, ATR-FTIR and X-ray Powder Diffraction. The molecular structure was determined by single crystal X-ray diffraction analysis at 100 K and 303 K. The compound consists of binuclear units where both Cu(II) atoms are linked by four syn-syn carboxylate bridges, showing a paddle-wheel unit. The role of C H⋯O hydrogen bonds in the establishment of its supramolecular network is discussed, comparing the resulting structural parameters at the two different temperatures. Finally, the thermal variation of XpT for compound 1 has also been studied, suggesting an antiferromagnetic Cu⋯Cu interaction (J = −311 cm−1), which agrees with the presence of four μ-κO-κO′ carboxylates bridging the metallic centers in the binuclear complex.

A new coordination polymer based on copper(II) and pyrazole (pzH) ligand, [CuCl2(ClpzH)2]n, has been obtained by a very easy synthesis and green reaction conditions using water as solvent. The compound was characterized by single crystal X-ray diffraction elemental analyses, infrared and UV–Vis spectroscopies. For the first time the C(2)-chlorination of the pyrazolyl ring keeping the protonation of the N(2)–H is reported. The polymeric crystal structure consists of a one dimensional infinite neutral chain in which the copper(II) atoms are six-coordinated in a slightly distorted octahedral geometry with two nitrogen and four chlorine atoms. In this structure, intermolecular interactions have been identified and studied. Extended structure analyses revealed a novel two-dimensional network supported by intermolecular N H Cl and C H Cl hydrogen bonds, in addition to the π–π stacking interactions.

The polymorphic crystallization and transformation behavior of extra virgin olive oil (EVOO) was examined by using differential scanning calorimetry (DSC) and X-ray diffraction with both laboratory-scale (XRD) and synchrotron radiation source (SR-XRD). The complex behavior observed was studied by previously analyzing mixtures composed by its main 2 to 6 triacylglycerol (TAG) components. Thus, component TAGs were successively added to simulate EVOO composition, until reaching a 6 TAGs mixture, composed by trioleoyl glycerol (OOO), 1-palmitoyl-2,3-dioleoyl glycerol (POO), 1,2-dioleoyl-3-linoleoyl glycerol (OOL), 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol (POL), 1,2-dipalmitoyl-3-oleoyl glycerol (PPO) and 1-stearoyl-2,3-dioleoyl glycerol (SOO). Molten samples were cooled from 25 °C to − 80 °C at a controlled rate of 2 °C/min and subsequently heated at the same rate. The polymorphic behavior observed in multicomponent TAG mixtures was interpreted by considering three main groups of TAGs with different molecular structures: triunsaturated OOO and OOL, saturated-unsaturated-unsaturated POO, POL and SOO, and saturated-saturated-unsaturated PPO. As confirmed by our previous work, TAGs belonging to the same structural group displayed a highly similar polymorphic behavior. EVOO exhibited two different β'-2 L polymorphic forms (β'2-2 L and β'1-2 L), which transformed into β'-3 L when heated. Equivalent polymorphic pathways were detected when the same experimental conditions were applied to the 6 TAG components mixture. Hence, minor components may not exert a strong influence in this case.

Three copper(II) acetate complexes with 4-phenylpyridine (4-Phpy), namely [Cu(MeCO2)2(4-Phpy)2(H2O)2] (1), [Cu(MeCO2)2(4-Phpy)2(H2O)1.5] (2) and [Cu(MeCO2)2(4-Phpy)]2 (3), were synthesized and characterized by analytical and spectroscopic methods. Experimental conditions as solvent or temperature determine the species obtained. Crystal and molecular structure of 2 was determined by X-ray diffraction. Compound 2 presents a singular structure, containing two crystallographic independent mononuclear units [Cu(MeCO2)2(4-Phpy)2(H2O)2] (2A) and [Cu(MeCO2)2(4-Phpy)2(H2O)] (2B) in its unit cell and each of these forms an independent 1-D chain through H-bonding.

Copper(II) bis(1,3-benzodioxole-5-carboxylate) adducts with bulky pyridines have been prepared from the reaction of copper(II) acetate with 1,3-benzodioxole-5-carboxylic acid (piperonylic acid, HPip) and an excess of pyridine derivatives (3-phenylpyridine, 3-Phpy, 4-phenylpyridine, 4-Phpy, or 4-benzylpyridine, 4-Bzpy). Using 3-Phpy or 4-Bzpy binuclear paddle wheel compounds ([Cu(μ-Pip)2(3-Phpy)]2 (1) and [Cu(μ-Pip)2(4-Bzpy)]2 (3), and mononuclear complexes [Cu(μ-Pip)2(3-Phpy)2(H2O)] (2) and {[Cu(Pip)2(4-Bzpy)2]}{[Cu(Pip)2(4-Bzpy)2](HPip)}·{4A}{4B} have been isolated. Mononuclear 2 can also be produced from 1 in presence of an excess of 3-Phpy, while low thermal treatment of 2 at 70 °C, in absence of solvent, reverts to the formation of 1. On the other hand, 4 presents a singular structure that contains two independent mononuclear units {4A} and {4B}. Working with 4-Phpy yields crystalline binuclear [Cu(μ-Pip)(Pip)(4-Phpy)2]2·4CH3OH (5). In this complex only half of the carboxylate ligands bridge copper atoms, being one of the rare examples of this flat core. Its crystal structure contains a significant fraction of volume filled with methanol that is partly lost simply by exposing the solid to air. However, this process is related to an irreversible structure collapse, showing that the intermolecular interactions after methanol removal are not enough to support a porous structure.

The effect of the PPh3 group in the antitumor activity of some new organometallic Ruthenium (II) complexes has been investigated. Several complexes of the type [Ru(II)(Cl)(PPh3)(Lig-N)], [Ru(II)(Cl)2(Lig-N)] (where Lig-N=pyridine derivate) and [Ru(II)(Cl)(PPh3)2], have been synthesized and characterized, and an important increment of the antitumor activity and cytotoxicity of the complexes due to the presence of PPh3 moiety has been demonstrated, affording IC50 values of 5.2 μM in HL-60 tumour cell lines. Atomic Force Microscopy, Circular Dichroism and Electrophoresis experiments have proved that these complexes can bind DNA resulting in a distortion of both secondary and tertiary structures. Ethidium bromide displacement Fluorescence Spectroscopy studies and Viscosity measurements support that the presence of PPh3 group induces intercalation interactions with DNA. Indeed, crystallographic analysis, suggest that intra-molecular π-π interactions could be involved in the intercalation within DNA base pairs. Furthermore, HPLC-MS studies have confirmed a strong interaction between Ruthenium complexes and proteins (Ubiquitin and Potato Carboxypeptidase Inhibitor -PCI-) including slower kinetic due to the presence of PPh3 moiety, which could have an important role in detoxification mechanism and others. Finally, Ion Mobility Mass Spectrometry (IMMS) experiments have proved that there is no change in the structural conformation of the proteins owing to their bonding to Ruthenium complexes. This seems particularly important in the case of PCI, that may be a suitable candidate for vehiculizing these complexes in a selective manner into tumour cells. In agreement with these results, further investigations should be carried out to clarify either there is a favoured binding to DNA or to specific proteins, thus to elucidate their main biological target.

The cyclopalladation of a series of symmetric diimines with the formula (RC6H4CHNZ)2, where Z = CH2 or (CH2)2OCH2 and R = p-Cl, p-OMe, p-NO2, and o-Cl, is described. Optimal conditions to obtain the dimetalated compounds were found to be palladium(II) acetate, in toluene, at 60 °C and with a reaction time of 2−4 h. The reactivity of the dimetalated compounds with monodentate, bidentate, and bis(monodentate) Lewis bases was also studied. The cytotoxic activity of some selected compounds was evaluated against a panel of adenocarcinoma cell lines (colon HCT116 and breast MCF7 and MDA-MB231). Compounds containing the fragment NCH2CH2OCH2CH2OCH2CH2N exhibited a remarkable cytotoxic activity in the three cancer cells assayed, but complexes containing the NCH2CH2N fragment showed no activity. It seems that the length and flexibility of the central saturated chain in the imine molecule, as well as its lipophilicity and hydrophilicity, explain the different cytotoxicity of the two series of coordination compounds here reported.