bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano‐Microporous Materials: Hydrothermal Synthesis of Zeolites
Authors: Valtchev Valentin , Mintova Svetlana 
Published: December 2011

AbstractThis review focuses on the synthesis, crystallization mechanism, and crystal engineering of silica‐based zeolites. The introduction section provides a brief historical overview of zeolite synthesis and points out the main families of microporous solids. The main body of the article comprises two interrelated parts. The first presents basic information related to the zeolite crystallization, namely, (i) the key constituents of a zeolite‐yielding system; (ii) the reactions upon the action of mineralizing agent (OH−and F−); and (iii) the fundamentals of zeolite crystallogenesis. Emphasis is laid on the nucleation process, which is still not well understood. New insights into the zeolite nucleation gained by using colloidal and dense gel systems are discussed. The second part of the survey deals with in situ zeolite crystal engineering. Initially, the synthesis of nanosized particles is considered and then methods for the growth of large, at least 50 µm, zeolite crystals are presented. Further, the control of the crystal morphology via fine tuning of the synthesis variables is discussed. Hybrid zeolites obtained by grafting of organic functionalities during the crystallization reaction are also reviewed. Finally, methods for the synthesis of zeolites with hierarchical porosity are illustrated. This part is subdivided into two sections presenting polycrystalline hierarchical porous structures and single mesopore–containing zeolite crystals.
Periodic Mesoporous Organosilicas
Authors: Yao Baodian , Zhao Dongyuan 
Published: December 2011

Abstract
Periodic mesoporous organosilicas (PMOs) represent a promising new class of organic–inorganic nanocomposite materials in which the organic and inorganic moieties are covalently linked and homogeneously distributed at molecular level. This review retrospected the discovery and development of PMOs in terms of rational synthesis based on the concept of supramolecular self‐assembly. The main focus is on precursors and crystal‐like PMOs. We also highlight the recent achievements regarding compositions and mesostructures, morphologies, and applications in the field. Furthermore, we present an outlook about the promising future perspectives of PMOs that result from the latest developments.
Semiconductor Nanocrystals: Doped Compositions
Authors: Vela Javier , Hollingsworth Jennifer A. 
Published: December 2011

Abstract
We review the state of the art in the field of semiconductor nanocrystal (SC NC) doping, with emphasis on cationic doping for modified optical and magnetic properties. Doping has the potential to greatly expand the already vast technological promise of SC NCs by allowing for the introduction of dopant‐specific or dopant‐modified properties. In the last several years, tremendous progress has been made with respect to both the understanding and implementation of SC NC–doping strategies. Here, we review the prevailing theoretical models (the “dopant extrusion model” and the “sticky surface model”) underpinning the current understanding of the process of dopant ion incorporation during NC growth. Further, we review the general synthetic approaches that have been developed in the context of this understanding, as well as many specific examples of SC NC–dopant systems, revealing both the successes and those that have fallen short in either achieving doping or fully demonstrating that doping was achieved. In support of this aim, we also provide a summary of the characterization methods (spectroscopic, structural, and chemical) that are critical for critiquing the doped system. We have necessarily focused on cationic doping as anionic doping has yet to be realized in a similar fashion. Further, the topic of electronic doping is only briefly addressed. While examples are reasonably abundant with respect to transition metal and lanthanide doping for modified magnetic/optical and optical properties respectively, permanent electronic doping of SC NCs has yet to be demonstrated. Finally, we identify (in addition to anionic and electronic doping) the topic areas that remain to be explored in this field of SC NC doping.
Supramolecular Materials: Metal–Quinonoid Complexes
Authors: Kim Sang Bok , Sweigart Dwight A. , Lotz Simon 
Published: December 2011

Abstract

Simple quinones such as hydroquinone, resorcinol, and catechol can be complexed to a transition metal through the aromatic π‐system. This review focuses on the manganese and rhodium complexes of hydroquinone (H
2
Q), which bind to the metal fragment through all six aromatic carbons (η
6
) to afford (H
2
Q)Mn(CO)
3
+
and (H
2
Q)Rh(COD)
+
. Both of these undergo facile deprotonation to give hydrogen‐bonded semiquinone complexes, which can be deposited on HOPG surfaces. A second deprotonation occurs with concomitant electron transfer to the metal to give anionic η
4
‐benzoquinone complexes that bind to other metals through the quinonoid oxygens. In this way, self‐assembly to metal–organic framework polymer materials results with the (benzoquinone)ML

n

−
moiety serving as the spacer. The resultant polymers are porous and can have tetrahedral, octahedral, and square pyramidal geometries. In the case of rhodium as the metal, the quinonoid complexes are excellent catalysts for carbon–carbon coupling from aryl boronic acids, and activated olefins and aldehydes. The rhodium species also forms self‐supporting coordination networks in the presence of main group alkoxides, and these function as catalysts for acetylene polymerization. The catalysts can also be deposited strongly on silica gel supports. An exciting application of this chemistry is the derivatization of the surfaces of magnetic nanoparticles (MNPs). In the case of superparamagnetic FePt and ferrite nanoparticles (NPs), the quinonoid–metal complexes bind to the surface and function as centers for the growth of coordination polymers. This provides multiple catalytic centers that are subject to magnetic decantation, and constitutes the first generalized methodology for the combination of organometallics with NP surfaces.
Functional Supramolecular Hybrid Materials
Authors: Rurack Knut , Martínez‐Máñez Ramón 
Published: December 2011

AbstractThe combination of suitable nanoscopic inorganic supports with supramolecular concepts and bioconjugation strategies opens up exciting perspectives for the development of bioinorganic and organic–inorganic hybrid materials with improved functionalities. Many of the examples from the period 2004 to mid‐2007 reviewed here bridge the gap between molecules, materials sciences, biochemistry, and nanotechnology. The synergistic use of these approaches has led to the advancement of various functions such as enhanced recognition, amplified signaling, the controlled assembly and disassembly of aggregates and 3‐D architectures. Many of the implemented active functions can be carried out in a reversible and directed fashion on purpose by triggering with an external stimulus. These ideas bring tunability to properties of inorganic solids and new perspectives of application to biochemical and supramolecular concepts. Classic inorganic chemistries such as metal or semiconductor nanoparticles, silica or carbon materials, and coordination chemistry are thus elevated to another level of sophistication and contribute significantly to frontier research areas in directed transport and delivery, nanoelectronics and mechanics, chip technology, smart materials, memory devices, and bioanalytics.
Nano/Microporous Materials: Mesoporous and Surface‐Functionalized Mesoporous Carbon
Authors: Wang Xiqing , Liang Chengdu , Dai Sheng 
Published: December 2011

Abstract
Mesoporous carbon materials, a category of porous carbons with pore size between 2 and 50 nm, have attracted considerable attention owing to their wide applications. There are many conventional methods available for the preparation of mesoporous carbons. Generally, the resulting mesoporous carbon materials have a broad pore size distribution. Carbon materials with uniform pore size can be prepared using porous silica gels or colloidal silica nanoparticles as hard templates. Periodically ordered mesoporous carbons are a recent addition to this category. Ordered mesoporous carbons can be made by a hard template method using ordered mesoporous silicas with three‐dimensionally connected pore structures (e.g., SBA‐15) as the templates. Self‐assembly of thermal decomposable block copolymers with thermosetting resol or novalac resin into mesostructured nanocomposites provides an alternative approach for the synthesis of ordered mesoporous carbons. The carbon materials obtained exhibit high Brunauer–Emett–Teller (BET) surface areas, controllable pore diameters with narrow pore size distribution, and large pore volumes. Efforts aimed toward surface modification of mesoporous carbons that integrate unique mesoporosity with other functionalities have led to many interesting materials and some promising results for applications. With the development of mesoporous and surface‐functionalized mesoporous carbon materials, numerous applications are awaiting the exploration of materials research scientists. Herein we summarize the recent progress in the synthesis and surface modification of mesoporous carbons, mainly on the carbon materials with uniform pore size and/or ordered structures.
Semiconductor/Ceramic Nanocomposites: Synthesis, Characterization, and Properties
Authors: Moore Joshua T. 
Published: December 2011

Abstract
A survey of the preparation of semiconductor nanocrystal‐ceramic nanocomposite materials and related nanostructured materials is provided. Nanocomposite materials described here contain elemental semiconductors (Si and Ge), II–VI and IV–VI semiconductors (ZnE, CdE, and PbE where E = S, Se, Te), and III–V semiconductors (GaE, AlE, and InE where E = N, P, As) embedded in various ceramic matrices. Semiconductor nanocrystals and nanoparticles were prepared using a variety of physical, chemical, and electrochemical synthesis strategies. Sol‐gel processing, and single‐ or multiple‐source precursors were used to prepare semiconductor nanoparticles with diameters as small as 2–4 nm or as large as 50–200 nm. Formation of the semiconductor nanophase was carried out by reduction of mixed‐metal oxides, pyrolysis of well‐characterized precursor molecules or in situ generated precursor complexes, chemical vapor deposition (CVD), and electrochemical reduction.
Semiconductor Nanowires
Authors: Korgel Brian A. 
Published: December 2011

Abstract
This review provides an overview of the synthesis, structural and chemical properties, and assembly and processing strategies of semiconductor nanowires. Vapor–liquid–solid (VLS), solution–liquid–solid (SLS), supercritical fluid–liquid–solid (SFLS) approaches that rely on the formation of a liquid metal–semiconductor eutectic to seed nanowire growth are covered. Nanowire growth from metal seed particles in the solid phase are also discussed, as well as chemical methods that rely on surfactants, self‐assembly, and directed crystallization processes. Structural details about the nanowires, including the crystallographic growth direction, common extended defects, and surface faceting are discussed. Routes to surface passivation by organic monolayers and compositional control of impurity doping and heterostructures—radial and axial—are presented, as well as more structurally complicated branched nanowire structures. Finally, an overview of nanowire processing and manipulation is offered, with a discussion about positioned growth, self‐assembly, and the potential impact of impurities on applications.
Monodisperse Magnetic Nanoparticles: Chemical Synthesis and Surface Modification
Authors: Xie Jin , Sun Shouheng 
Published: December 2011

Abstract
Magnetic nanoparticles, due to their prospective applications in data storage, drug delivery, hyperthermia, and magnetic resonance imaging, have attracted considerable attention in the past decade. From aqueous‐phase condensation to organic‐phase thermal decomposition, the synthesis of magnetic nanoparticles has been greatly improved. Nowadays, one can readily synthesize monodisperse magnetic nanoparticles with controlled sizes, shapes, and magnetic properties. In this article, we first briefly describe the general synthesis of monodisperse nanoparticles, and then focus on the synthesis of magnetic nanoparticles via thermal decomposition of metal precursors. The nanoparticles are grouped into ferrite, metallic, alloy, and multicomponent categories, and the mechanism for the formation of nanoparticles with critical parameters in determining size, shape, and multifunctionality is discussed. We further summarize the chemistry used for nanoparticle surface functionalization and briefly discuss the potential applications of these magnetic nanoparticles in biomedicine.
Inorganic Nanomaterials Synthesis Using Alkalide Reduction
Authors: Wagner Michael J. 
Published: December 2011

AbstractChemical (solution) methods of nanomaterial synthesis offer the advantages of simplicity, stoichiometric control, ease of scale‐up, and the possibilities of size control and narrow size distributions. Of the many solution methods of making nanoparticles, the reduction of metal salts by alkalides or electrides, generally referred to asalkalide reduction, is particularly promising due to its ability to protect highly oxyphilic elements and its use of the most power reductants possible in any given solvent. This makes it general across the periodic table including the early transition metals and rare earth elements. In fact, to date, it is the only solution method shown to be capable of synthesizing lanthanide metal nanoparticles. Binary and higher order phase nanomaterials are also possible by the simultaneous alkalide reduction of multiple elements. Nanoscale oxides and nitrides can be formed by reacting nanomaterials made by alkalide reduction with the appropriate gas. Spheroidal nanoparticles as small as ∼1 nm in diameter can be synthesized by this method as can rods up to ∼1 µm in length. The current practice and capabilities of highly versatile synthetic routes to nanomaterials are outlined in this article.
Gold in Homogeneous Catalysis
Authors: Jiménez‐Núñez Eloása , Echavarren Antonio M. 
Published: December 2011

Abstract
The important types of transformations catalyzed by homogeneous Au(I) and Au(III) complexes or salts are reviewed. The reactions are organized mechanistically on the basis of the main functional group being activated by the gold catalyst. Particular emphasis is given on the most general reactions for the formation of CC bonds.
Scandium, Yttrium and the Lanthanides: Applications
Authors: Cotton Simon A. 
Published: December 2011

Abstract

New applications are increasingly found for scandium, yttrium, and the lanthanides and their compounds. Among reagents in synthetic organic chemistry, LaNi
5
is a versatile hydrogenation catalyst. SmI
2
is an important one‐electron reducing agent, and lanthanide triflates, Ln(CF
3
OSO
3
)
3
(Ln = Sc, Y, or lanthanide), are recyclable Lewis acid catalysts, which operate in aqueous conditions. Organocerium compounds are valuable, mild alkylating agents, while using cerium chloride in combination with NaBH
4
and LiAlH
4
permits a range of reductions to be carried out. (NH
4
)
2
[Ce(NO
3
)
6
] is an established oxidant for which new applications are being found. The alloys SmCo
5
and Sm
2
Co
17
have been used to produce magnetic materials that are very powerful for their size, though partly superseded by cheaper Nd
2
Fe
14
B material, while strongly paramagnetic salts of Dy
3+
or Gd
3+
permit attainment of extremely low temperatures through adiabatic demagnetization. The mixed metal oxide YBa
2
Cu
3
O

7−
x

was the first material to superconduct above 77 K, revolutionizing understanding; new materials are being developed, most recently fluoride‐doped oxypnictides LaFeAsO. In addition to gadolinium complexes as MRI contrast agents, other lanthanide compounds find medicinal application, including cerium compounds in wound and burn treatment. In terms of quantity, the most important application of lanthanide compounds is lanthanide‐exchanged zeolites as catalysts in the petrochemical industry, notably in cracking, but cerium oxide is an important component of catalytic converters in automobile exhausts. The ability of LaNi
5
to absorb hydrogen reversibly has been vital to nickel–metal hydride (NiMH) batteries, while yttrium aluminum garnet (Y
3
Al
5
O
12
) is widely used as a host material in lasers and phosphors. Yttria‐stabilized zirconia (YSZ) is a ceramic material used as the electrolyte material in solid oxide fuel cells (SOFCs) and in sensors in car exhaust systems.
Medicinal Inorganic Chemistry: An Introduction
Authors: Thompson Katherine H. 
Published: December 2011

AbstractMetal ions in clinical use today include bismuth compounds, which have been in use for over a hundred years, lithium carbonate, which has been in use for over 50 years, and cisplatin, which was introduced almost 40 years ago. “Metals in medicine” also covers a wealth of newer diagnostic and therapeutic compounds, such as gadolinium‐based contrast agents for magnetic resonance imaging (MRI), samarium‐based compounds for relief of bone pain in intractable cancer, and lanthanum carbonate for the treatment of hyperphosphatemia. In the process, mystical/magical use of metals in medicine has given way to rational design and testing of new metallopharmaceutical compounds. Advances in our understanding of bioinorganic chemistry and increasingly sensitive analytical instrumentation enable an accelerated pace of development in medicinal inorganic chemistry.
Calculation of Bonding Properties
Authors: Frenking Gernot , von Hopffgarten Moritz 
Published: December 2011

Abstract

The bonding situation in four classes of compounds is analyzed with modern charge and energy decomposition methods. The nature of the bonding in the diatomic species H
2
, N
2
, CO, and BF is investigated with the energy decomposition analysis (EDA). The electronic structure of the heavy‐atom homologs of acetylene HEEH (E = SiPb) is investigated with the help of an orbital analysis and EDA calculations. Metal–ligand bonding in isoelectronic metal hexacarbonyls TM(CO)
6
q
(TM
q
= Hf
2−
, Ta
−
, W, Re
+
, Os
2+
, Ir
3+
) is the subject of a detailed EDA study. The bonding situation in the unusual 12‐fold coordinated transition‐metal compound [Mo(ZnH)
12
] is analyzed with the AIM (atoms in molecules), EDA, and MO methods. The results of the electronic structure analyses build a bridge between the heuristic bonding models, which are ubiquitously used in inorganic chemistry and accurate quantum chemical calculations.
Multiconfigurational Quantum Mechanics (QM) for Heavy Element Compounds
Authors: Roos Björn O. 
Published: December 2011

AbstractOne frequently used quantum chemical approach for the studies of transition metal and other heavy element compounds is the complete active space self consistent field (CASSCF) method in combination with multiconfigurational second‐order perturbation theory (CASPT2). Here, we describe this method and some of its typical applications. The basic idea is to construct a wave function that gives a qualitatively correct description of the electronic structure already at the lowest level of theory. This should be possible for all sorts of electronic states independent of spin multiplicity and excitation level. Strong mixing of configurations makes it necessary to use a multiconfigurational approach in such cases. It should also be possible to use for all atoms of the periodic system. The CASSCF wave function fulfills, in principle, this requirement because it is full configuration interaction (CI), albeit in a limited space of active orbitals. The addition of dynamic electron correlation is necessary to give quantitative results. The suggested solution is to compute this energy using second‐order perturbation theory (CASPT2) because it is relatively simple and allows applications to a wide variety of systems and many electrons. Relativistic corrections are included using a Douglas‐Kroll‐Hess Hamiltonian. The method is scrutinized and illustrated by some applications in transition metal and actinide chemistry.
Approximate Density Functionals: Which Should I Choose?
Authors: Rappoport Dmitrij , Crawford Nathan R. M. , Furche Filipp , Burke Kieron 
Published: December 2011

Abstract
Density functional methods have a long tradition in inorganic and bioinorganic chemistry. We introduce the density functional machinery and give an overview of most popular approximate exchange‐correlation (XC) functionals. We present comparisons of density functionals for energies, structures, and reaction barriers of inorganic and bioinorganic systems, giving guidance on the title question. New development directions and current trends in density functional theory (DFT) are reviewed.
Broken Symmetry States of Iron—Sulfur Clusters
Authors: Noodleman Louis , Case David A. 
Published: December 2011

AbstractAfter presenting a general introduction to the structures and physical properties of dinuclear and polynuclear iron sulfur clusters, we discuss the relationship between the broken symmetry model within density functional theory (DFT), and the energies and properties of related pure spin states. The methodology for calculating and the physical significance of Heisenberg coupling parameters (J) and spin‐dependent delocalization parameters (B) are developed. The interaction energy of the active site quantum cluster with the protein and solvent environment is treated with a single step procedure based on the classical Poisson–Boltzmann (PB equation). Redox potentials of various high‐potential 4Fe4S and ferredoxin proteins are calculated with DFT/PB methods. The electronic and spin‐coupling structure of oxidized high‐potential (HIPIP) proteins is examined, and it is shown that two distinct electronic structures are possible. These contrasting electronic structures may have implications for the structural stability of oxidized HIPIP. For the Fe protein of nitrogenase, the redox potential and spin state of the super‐reduced form are calculated, and it is argued that this all‐ferrous state is probably not physiologically accessible. The redox potential and electronic structure of the FeMo cofactor of the MoFe protein of nitrogenase are examined for the “resting” state. A very small spin density at the central atom is very feasible. The central atom could be XC, N, O, but C, N are most probable, despite the absence of an observable ENDOR signal for the central atom. The spin‐density for a central atom should be much higher for the 2e‐reduced FeMo cofactor when a ligand is bound, and we have tested this for bound allylic alcohol. Three different ligand‐cluster binding structures are characterized by geometry, energy, and spin distribution.