Observation of Slow Magnetic Relaxation in Discrete Dysprosium Cubane

A discrete dysprosium cubane has been prepared and structurally characterized Slow relaxation of magnetization in this complex is observed, which may stimulate further investigations into the dynamics of magnetization in lanthanide clusters with different topologies.

Templated assembly of mu(5)-CO32- decanuclear praseodymium and neodymium clusters through spontaneous fixation of atmospheric carbon dioxide

Reactions of Ln(III) acetate (Ln = Pr and Nd) and a polydentate Schiff-base in a mixture of methanol and acetonitrile resulted in the unprecedented assembly of novel Ln(10) aggregates containing two Ln(5) pentagons templated by mu(5)-CO32-, introduced via spontaneous fixation of atmospheric carbon dioxide. Magnetic analysis using an expression including the ligand field effects and molecular field approximation indicates weak antiferromagnetic coupling between the metal ions. This synthetic approach may represent a promising new route toward the design of new lanthanide clusters and novel multifunctional materials.

Heterometallic Complexes as Models of Enzymatic Active Sites

This dissertation describes studies on two multinucleating ligand architectures: the first scaffold was designed to support tricopper complexes, while the second platform was developed to support tri- and tetrametallic clusters.

In Chapter 2, the synthesis of yttrium (and lanthanide) complexes supported by a tripodal ligand framework designed to bind three copper centers in close proximity is described. Tricopper complexes were shown to react with dioxygen in a 1:1 [Cu₃]/O₂ stoichiometry to form intermediates in which the O–O bond was fully cleaved, as characterized via UV-Vis spectroscopy and determination of the reaction stoichiometry. Pre-arrangement of the three Cu centers was pivotal to cooperative O₂ activation, as mono-copper complexes reacted differently with dioxgyen. The reactivity of the observed intermediates was studied with various substrates (reductants, O-atom acceptors, H-atom donors, Brønsted acids) to determine their properties. In Chapter 3, the reactivity of the same yttrium-tricopper complex with nitric oxide was explored. Reductive coupling to form a trans-hyponitrite complex (characterized by X-ray crystallography) was observed via cooperative reactivity by an yttrium and a copper center on two distinct tetrametallic units. The hyponitrite complex was observed to release nitrous oxide upon treatment with a Brønsted acid, supporting its viability as an intermediate in nitric oxide reduction to nitrous oxide.

In Chapter 4, a different multinucleating ligand scaffold was employed to synthesize heterometallic triiron clusters containing one oxide and one hydroxide bridges. The effects of the redox-inactive, Lewis acidic heterometals on redox potential was studied by cyclic voltammetry, unveiling a linear correlation between redox potential and heterometal Lewis acidity. Further studies on these complexes showed that the Lewis acidity of the redox-inactive metals also affected the oxygen-atom transfer reactivity of these clusters. Comparisons of this reactivity with manganese systems, collaborative efforts to reassign the structures of related manganese oxo-hydroxo clusters, and synthetic attempts to access related dioxo clusters are also described.

In Appendix A, ongoing efforts to synthesize new clusters supported by the same multinucleating ligand platform are described. Studies of novel approaches towards ligand exchange in tetrametallic clusters and incorporation of new supporting and bridging ligand motifs in trinuclear complexes are presented.

Novel polyoxometalate-templated, 3-D supramolecular networks based on lanthanide dimers: Synthesis, structure, and fluorescent properties of [Ln(2)(DNBA)(4)(DMF)(8)][Mo6O19] (DNBA=3,5-dinitrobenzoate)

The spherical Lindquist type polyoxometalate, Mo6O192-, has been used as a noncoordinating anionic template for the construction of novel three-dimensional lanthanide-aromatic monocarboxylate dimer supramolecular networks [Ln(2)(DNBA)(4)(DMF)(8)][Mo6O19] (Ln = La 1, Ce 2, and Eu 3, DNBA = 3,5-dinitrobenzoate, DMF = dimethylformamide). The title compounds are characterized by elemental analyses, IR, and single-crystal X-ray diffractions. X-ray diffraction experiments reveal that two Ln(III) ions are bridged by four 3,5-dinitrobenzoate anions as asymmetrically bridging ligands, leading to dimeric cores, [Ln(2)(DNBA)(4)(DMF)(8)](2+); [Ln(2)(DNBA)(4)(DMF)(8)](2+) groups are joined together by pi-pi stacking interactions between the aromatic groups to form a two-dimensional grid-like network; the 2-D supramolecular layers are further extended into 3-D supramolecular networks with 1-D box-like channels by hydrogen-bonding interactions, in which hexamolybdate polyanions reside. The compounds represent the first examples of 3-D carboxylate-bridged lanthanide dimer supramolecular "host" networks formed by pi-pi stacking and hydrogen-bonding interactions encapsulating noncoordinating "guest" polyoxoanion species. The fluorescent activity of compound 3 is reported.

Facile in situ synthesis of nanofluids based on ionic liquids and copper oxide clusters and nanoparticles

Two stable nanofluids comprising of mixed valent copper(_I,_II) oxide clusters (<1 nm) suspended in 1-butyl-3-methylimidazolium acetate, [C(₄)mim][OAc], and copper(_II) oxide nanoparticles (<50 nm) suspended in trioctyl(dodecyl) phosphonium acetate, [P-₈₈₈₁₂][OAc], were synthesised in a facile one-pot reaction from solutions of copper(_II) acetate hydrate in the corresponding ionic liquids. Formation of the nanostructures was studied using ¹³C NMR spectroscopy and differential scanning calorimetry (DSC). From a solution of Cu(OAc)₂ in 1-ethyl-3-methylimidazolium acetate, [C₂mim][OAc], crystals were obtained that revealed the structure of [C₂mim][Cu₃(OAc)₅(OH)₂(H₂O)]center dot H₂O, indicating the formation of copper hydroxo-clusters in the course of the reaction. Synthesised nanostructures were studied using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Physical properties of the prepared IL-nanofluids were examined using IR and UV-VIS spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and densitometry. 

Individual firms and regional business clusters : the HRM advantage in rent generation

Much of the literature on clusters has focused on the economic advantages of clusters and how these can be achieved in terms of competition, regional development and local spillovers. Some studies have focused at the level of the individual firm however human resource management (HRM) in individual clustered firms has received scant attention. This paper innovatively utilises the extended Resource Based View (RBV) of the firm as a framework to conceptualise the human resource processes of individual firms within a cluster. RBV is argued as a useful tool as it explains external rents outside a firm’s boundaries. The paper concludes that HRM can assist in generating rents for firms and clusters more broadly when the function supports valuable interfirm relationships important for realising inter-firm advantages.

Working memory correlates of three symptom clusters in schizophrenia

Examined whether discrete working memory deficits underlie positive, negative and disorganised symptoms of schizophrenia. 52 outpatients (mean age 37.5 yrs) with schizophrenia were studied using items drawn from the Positive and Negative Syndrome Scale (PANSS). Linear regression and correlational analyses were conducted to examine whether symptom dimension scores were related to performance on several tests of working memory function. Severity of negative symptoms correlated with reduced production of words during a verbal fluency task, impaired ability to hold letter and number sequences on-line and manipulate them simultaneously, reduced performance during a dual task, and compromised visuospatial working memory under distraction-free conditions. Severity of disorganisation symptoms correlated with impaired visuospatial working memory under conditions of distraction, failure of inhibition during a verbal fluency task, perseverative responding on a test of set-shifting ability, and impaired ability to judge the veracity of simple declarative statements. The present study provides evidence that the positive, negative and disorganised symptom dimensions of the PANSS constitute independent clusters, associated with unique patterns of working memory impairment.

Creative clusters and universities : the cluster concept in economics and geography

This paper considers the history of the cluster concept in urban economic geography, and its relationship to recent debates about creative cities. It then looks at the role that universities can play in the development of a creative cluster, as well as some of the potential pitfalls.

Understanding the creative economy : a tale of two cities clusters

This article investigates underlying constraints within China’s creative economy. Drawing on two studies of creative clusters in Suzhou and Foshan, it identifies the importance of knowledge transfer and internationalization to the generation of higher value-added products and services. Both examples illustrate relationships between resources, activities, routines and entrepreneurship. The article argues that the examples notwithstanding, the vast majority of what is accounted for in data collection as China’s creative industries are more appropriately cultural industries. The focus on cultural industries drives local development and increases land values but the benefits are rarely dispersed internationally or into the broader economy.

Great adaptations : China's creative clusters and the new social contract

The transformation of China's urban landscape has witnessed a boom in cultural adaptation, namely the adaptation of a Western idea, the creative cluster. This chapter examines the formatting of hundreds of creative clusters-art centres, animation bases, cultural zones, and incubators. The cluster has important implications for how we understand China going forward into the second decade of the 21st century. The cluster phenomenon has resulted in to a substantive remaking of the social contract, between officials, entrepreneurs, local residents, academics-and most significantly cultural producers. However, these processes of adaption are mostly driven by real estate developers working in partnership with local government officials. Cut and paste design is the fast road to completion. In this sense, the description 'creative' may well be redundant.

The Evolution of the creative industries : creative clusters, creative citizens and social network markets 創意產業的演化 : 創意集群 ,創意公民, 社會網絡市場 [published in Chinese]

The creative industries are important because they are clustered at the point of attraction for a billion or more young people around the world. They're the drivers of demographic, economic and political change. They start from the individual talent of the creative artist and the individual desire and aspiration of the audience. These are the raw materials for innovation, change and emergent culture, scaled up to form new industries and coordinated into global markets based on social networks.

Multivariate methods to identify cancer-related symptom clusters

Multivariate methods are required to assess the interrelationships among multiple, concurrent symptoms. We examined the conceptual and contextual appropriateness of commonly used multivariate methods for cancer symptom cluster identification. From 178 publications identified in an online database search of Medline, CINAHL, and PsycINFO, limited to articles published in English, 10 years prior to March 2007, 13 cross-sectional studies met the inclusion criteria. Conceptually, common factor analysis (FA) and hierarchical cluster analysis (HCA) are appropriate for symptom cluster identification, not principal component analysis. As a basis for new directions in symptom management, FA methods are more appropriate than HCA. Principal axis factoring or maximum likelihood factoring, the scree plot, oblique rotation, and clinical interpretation are recommended approaches to symptom cluster identification.

Evolution and change in industrial clusters : an analysis of Hsinchu and Sophia Antipolis

The aim of this paper is to advance understandings of the processes of cluster-building and evolution, or transformative and adaptive change, through the conscious design and reflective activities of private and public actors. A model of transformation is developed which illustrates the importance of actors becoming exposed to new ideas and visions for industrial change by political entrepreneurs and external networks. Further, actors must be guided in their decision-making and action by the new vision, and this requires that they are persuaded of its viability through the provision of test cases and supportive resources and institutions. In order for new ideas to become guiding models, actors must be convinced of their desirability through the portrayal of models as a means of confronting competitive challenges and serving the economic interests of the city/region. Subsequent adaptive change is iterative and reflexive, involving a process of strategic learning amongst key industrial and political actors.