11 research outputs found
From 1D coordination polymers to Metal Organic Frameworks by the use of 2-pyridyl oximes.
The synthesis and characterization of coordination polymers and metal-organic frameworks (MOFs) has attracted a significant interest over the last decades due to their fascinating physical properties, as well as their use in a wide range of technological, environmental, and biomedical applications. The initial use of 2-pyridyl oximic ligands such as pyridine-2 amidoxime (H2pyaox) and 2-methyl pyridyl ketoxime (Hmpko) in combination with 1,2,4,5-benzene tetracarboxylic acid (pyromellitic acid), H4pma, provided access to nine new compounds whose structures and properties are discussed in detail. Among them, [Zn2(pma)(H2pyaox)2(H2O)2]n (3) and [Cu4(OH)2(pma)(mpko)2]n (9) are the first MOFs based on a 2-pyridyl oxime with 9 possessing a novel 3,4,5,8-c net topology. [Zn2(pma)(H2pyaox)2]n (2), [Cu2(pma)(H2pyaox)2(DMF)2]n (6), and [Cu2(pma)(Hmpko)2(DMF)2]n (8) join a small family of coordination polymers containing an oximic ligand. 9 exhibits selectivity for FeIII ions adsorption, as was demonstrated by a variety of techniques including UV-vis, EDX, and magnetism. DC magnetic susceptibility studies in 9 revealed the presence of strong antiferromagnetic interactions between the metal centers, which lead to a diamagnetic ground state; it was also found that the magnetic properties of 9 are affected by the amount of the encapsulated Fe3+ ions, which is a very desirable property for the development of magnetism-based sensors
Cross-linguistic patterns in the acquisition of quantifiers.
Learners of most languages are faced with the task of acquiring words to talk about number and quantity. Much is known about the order of acquisition of number words as well as the cognitive and perceptual systems and cultural practices that shape it. Substantially less is known about the acquisition of quantifiers. Here, we consider the extent to which systems and practices that support number word acquisition can be applied to quantifier acquisition and conclude that the two domains are largely distinct in this respect. Consequently, we hypothesize that the acquisition of quantifiers is constrained by a set of factors related to each quantifier's specific meaning. We investigate competence with the expressions for "all," "none," "some," "some…not," and "most" in 31 languages, representing 11 language types, by testing 768 5-y-old children and 536 adults. We found a cross-linguistically similar order of acquisition of quantifiers, explicable in terms of four factors relating to their meaning and use. In addition, exploratory analyses reveal that language- and learner-specific factors, such as negative concord and gender, are significant predictors of variation.This is the author accepted manuscript. The final version is available from the National Academy of Sciences via http://dx.doi.org/10.1073/pnas.160134111
Rare Nuclearities and Unprecedented Structural Motifs in Manganese Cluster Chemistry from the Combined Use of Di-2-Pyridyl Ketone with Selected Diols
The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3)∙2DMF∙H2O (1∙2DMF∙H2O), [Mn11O2(OH)2{(py)2CO2}5(mpd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3) (2), [Mn12O4(OH)2{(py)2CO2}4(mpd)2(Me3CCO2)4(NO3)4(H2O)6](NO3)2∙2MeCN (3∙2MeCN), [Mn4(OMe)2{(py)2C(OMe)O}2(2-hp)2(NO3)2(DMF)2] (4), and [Mn7{(py)2CO2}4(2-hp)4(NO3)2(DMF)2](ClO4)∙DMF (5∙DMF) ((py)2CO22− and (py)2C(OMe)O− = gem-diol and hemiketal derivatives of di-2-pyridyl ketone, pdH2 = 1,3-propanediol, mpdH2 = 2-metly-1,3-propanediol, 2-hpH2 = 2-(hydroxymethyl)phenol). Complexes 1 and 2 are isostructural, possessing an asymmetric [MnIII5MnII6(μ4-O)(μ3-O)(μ3-OH)(μ-OH)(μ3-OR)2(μ-OR)10(μ-N3)]8+ core. Compound 3 is based on a multilayer [MnIII8MnII4(μ4-O)2(μ3-O)2(μ3-OH)2(μ-OR)12]10+ core, while complex 4 comprises a defective dicubane core. The crystal structure of 5 reveals that it is based on an unusual non-planar [MnIII5MnII2(μ-OR)12]7+ core with a serpentine-like topology. Direct current (dc) magnetic susceptibility studies revealed the presence of dominant antiferromagnetic exchange interactions in complex 3, while ferromagnetic coupling between the Mn ions was detected in the case of compound 5. Fitting of the magnetic data for complex 4 revealed weak antiferromagnetic interactions along the peripheral MnII∙∙∙MnIII ions (Jwb = −0.33 (1) cm−1) and ferromagnetic interactions between the central MnIII∙∙∙MnIII ions (Jbb = 6.28 (1) cm−1)
Heterometallic Mn<sup>III</sup><sub>4</sub>Ln<sub>2</sub> (Ln = Dy, Gd, Tb) Cross-Shaped Clusters and Their Homometallic Mn<sup>III</sup><sub>4</sub>Mn<sup>II</sup><sub>2</sub> Analogues
The employment of di-2-pyridyl ketone,
(py)<sub>2</sub>CO, in heterometallic Mn/4f and homometallic Mn cluster
chemistry has yielded six Mn<sup>III</sup><sub>4</sub>Ln<sub>2</sub> and two Mn<sup>III</sup><sub>4</sub>Mn<sup>II</sup><sub>2</sub> structurally
related clusters, namely, [Mn<sub>4</sub>Ln<sub>2</sub>O<sub>2</sub>{(py)<sub>2</sub>CO<sub>2</sub>}<sub>4</sub>(NO<sub>3</sub>)<sub>2</sub>(RCO<sub>2</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>6</sub>](NO<sub>3</sub>)<sub>2</sub> (Ln = Gd, <b>1</b>, <b>5</b>; Dy, <b>2</b>; Tb, <b>3</b>; R = Et, <b>1</b>–<b>3</b>; Me, <b>5</b>), [Mn<sub>4</sub>Dy<sub>2</sub>O<sub>2</sub>{(py)<sub>2</sub>CO<sub>2</sub>}<sub>4</sub>(NO<sub>3</sub>)<sub>4</sub>(EtCO<sub>2</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>3</sub>(MeOH)]·0.7MeOH·0.8H<sub>2</sub>O (<b>4</b>·0.7MeOH·0.8H<sub>2</sub>O), [Mn<sub>4</sub>Gd<sub>2</sub>O<sub>2</sub>{(py)<sub>2</sub>CO<sub>2</sub>}<sub>4</sub>(NO<sub>3</sub>)<sub>4</sub>(C<sub>6</sub>H<sub>4</sub>ClCO<sub>2</sub>)<sub>2</sub>(MeOH)<sub>2</sub>(py)<sub>2</sub>]·2MeOH (<b>6</b>·2MeOH), [Mn<sub>6</sub>O<sub>2</sub>{(py)<sub>2</sub>CO<sub>2</sub>}<sub>4</sub>(py)<sub>4</sub>(H<sub>2</sub>O)<sub>4</sub>](ClO<sub>4</sub>)<sub>4</sub>·4H<sub>2</sub>O (<b>7</b>·4H<sub>2</sub>O), and [Mn<sub>6</sub>O<sub>2</sub>{(py)<sub>2</sub>CO<sub>2</sub>}<sub>4</sub>(NO<sub>3</sub>)<sub>4</sub>(py)<sub>4</sub>] (<b>8</b>), where (py)<sub>2</sub>CO<sub>2</sub><sup>2–</sup> is the dianion of the <i>gem</i>-diol derivative of (py)<sub>2</sub>CO. The compounds possess a new
type of cross-shaped structural core, which in the case of <b>1</b>–<b>6</b> is essentially planar, whereas in <b>7</b> and <b>8</b> it deviates from planarity. Clusters <b>1</b>–<b>6</b> are rare examples of Mn/4f species bearing
(py)<sub>2</sub>CO or its derivatives, despite the fact that this
ligand has been well-studied and proven a rich source of more than
200 metal compounds so far. Variable-temperature, solid-state direct-current
and alternating-current magnetization studies were performed on complexes <b>1</b>–<b>5</b>, <b>7</b>, and <b>8</b> revealing that the dominant exchange interactions between the metal
ions are antiferromagnetic and indicating ground-state spin values
of <i>S</i> = 5 (for <b>1</b>), 6 (for <b>5</b>), and 2 (for <b>7</b> and <b>8</b>)
On the role of pragmatics in child-directed speech for the acquisition of verb morphology
Lituanistikos katedraUžsienio kalbų, lit. ir vert. s. katedraVytauto Didžiojo universiteta
Cross-linguistic patterns in the acquisition of quantifiers
Learners of most languages are faced with the task of acquiring words to talk about number and quantity. Much is known about the order of acquisition of number words as well as the cognitive and perceptual systems and cultural practices that shape it. Substantially less is known about the acquisition of quantifiers. Here, we consider the extent to which systems and practices that support number word acquisition can be applied to quantifier acquisition and conclude that the two domains are largely distinct in this respect. Consequently, we hypothesize that the acquisition of quantifiers is constrained by a set of factors related to each quantifier's specific meaning. We investigate competence with the expressions for "all," "none," "some," "some. not," and "most" in 31 languages, representing 11 language types, by testing 768 5-y-old children and 536 adults. We found a cross-linguistically similar order of acquisition of quantifiers, explicable in terms of four factors relating to their meaning and use. In addition, exploratory analyses reveal that language-and learner-specific factors, such as negative concord and gender, are significant predictors of variationLituanistikos katedraVytauto Didžiojo universiteta
Research data supporting "Cross-linguistic patterns in the acquisition of quantifiers"
Response_Data.csv: Participant responses ('correct' or 'incorrect') to sentences with quantifiers ('all', 'none', 'some', 'some...not', 'most') in 31 languages presented in the context of different visual displays. Item_Coding.csv: How sentences with quantifiers ('all', 'none', 'some', 'some...not', 'most') were coded.European Cooperation in Science and Technology - COST [COST Action A33