Relationship between Transition-Metal Hydride Bond Lengths and Stretching Wavenumbers.

Here it is demonstrated that there is a linear relationship between the terminal 3d metal hydride stretching wavenumber ν and the metal hydride distance reported to date: ν ∼ (-1.05 + 3.35) × 10 cm.

Exploring the utility of ultrasound to assess disuse atrophy in different muscles of the lower leg.

Background: Skeletal muscle is a highly plastic tissue crucial for many functions associated with whole-body health across the life course. Magnetic resonance imaging (MRI) is the current gold standard for measuring skeletal muscle size. However, MRI is expensive, and access to facilities is often limited.

Hard Candy Production and Quality Parameters: A review.

Hard candies are sugar confections comprising mainly water and sucrose. Corn syrup, colorants and flavors are also usually added to hard candy formulations. The production of hard candy requires heating of the ingredients to very high temperatures to reduce moisture content and subsequent cooling to obtain a solid matrix.

Mechanochemical Synthesis of Chromium(III) Complexes Containing Bidentate PN and Tridentate P-NH-P and P-NH-P' Ligands.

Chromium(III) complexes bearing bidentate {NH(CH)PPh: PN, ()-[NH(CHPh)PPh]: P'N} and tridentate [PhP(CH)N(H)(CH)PPh: P-NH-P, ()-(Pr)PCHCHN(H)CH(Ph)CH(Ph)PPh: P-NH-P'] ligands have been synthesized using a mechanochemical approach. The complexes {-[Cr(PN)Cl]Cl (), -[Cr(P'N)Cl]Cl (), -Cr(P-NH-P)Cl (), and -Cr(P-NH-P')Cl ()} were obtained in high yield (95-97%) the grinding of the respective ligands andthe solid Cr(III) ion precursor [CrCl(THF)] with the aid of a pestle and mortar, followed by recrystallization in acetonitrile. The isolated complexes are high spin.

Reactivity umpolung (reversal) of ligands in transition metal complexes.

The success and power of homogeneous catalysis derives in large part from the wide choice of transition metal ions and their ligands. This tutorial review introduces examples where the reactivity of a ligand is completely reversed (umpolung) from Lewis basic/nucleophilic to acidic/electrophilic or vice versa on changing the metal and co-ligands. Understanding this phenomenon will assist in the rational design of catalysts and the understanding of metalloenzyme mechanisms.

Ligand Determines the Stability of Paramagnetic Manganese(II) Hydrides of the Type -[MnH(L)(dmpe)] Where L is PMe, CH, or CO.

Paramagnetic metal hydride (PMH) complexes play important roles in catalytic applications and bioinorganic chemistry. 3d PMH chemistry has largely focused on Ti, Mn, Fe, and Co. Various Mn PMHs have been proposed as intermediates in catalysis, but isolated Mn PMHs are limited to dimeric high-spin Mn structures with bridging hydrides.

Triphasic 3D In Vitro Model of Bone-Tendon-Muscle Interfaces to Study Their Regeneration.

The transition areas between different tissues, known as tissue interfaces, have limited ability to regenerate after damage, which can lead to incomplete healing. Previous studies focussed on single interfaces, most commonly bone-tendon and bone-cartilage interfaces. Herein, we develop a 3D in vitro model to study the regeneration of the bone-tendon-muscle interface.

Density Functional Theory Study on the Selective Reductive Amination of Aldehydes and Ketones over Their Reductions to Alcohols Using Sodium Triacetoxyborohydride.

Reductive amination is one of the most important methods to synthesize amines, having a wide application in the pharmaceutical, fine chemicals, and materials industries. In general, the reaction begins with dehydration between a carbonyl compound and an amine compound, forming an imine, which is then reduced to an alkylated amine product. Sodium triacetoxyborohydride (STAB) is a popular choice for the reducing agent as it shows selectivity for imines over aldehydes and ketones, which is particularly important in direct reductive amination where the imine and carbonyl compounds are present concurrently.

A Plausible Mechanism for the Iridium-Catalyzed Hydrogenation of a Bulky -Aryl Imine in the ()-Metolachlor Process.

The hydrogenation of -(2-ethyl-6-methylphenyl)-1-methoxypropan-2-imine is the largest-scale asymmetric catalytic process for the industrial production of agrochemical ()-metolachlor. The challenging hydrogenation across the sterically crowded carbon-nitrogen double bond was achieved using a mixture of [IrCl(COD)], (,)-Xyliphos, NBuI and acetic acid. Acetic acid was critical in achieving excellent productivity and activity.

Electronic insights into aminoquinoline-based PNN ligands: protonation state dictates geometry while coordination environment dictates N-H acidity and bond strength.

A variety of transition metal complexes bearing aminoquinoline PNH'-R ligands R = Ph (L1H), Cy (L2H) and their amido analogues are reported for rhodium(I) ([Rh(L1H)(PPh)]1 and Rh(L1)(PPh) 2), cobalt(II) (Co(L2)(Cl) 3), and iron(II) ([Fe(L1H)]5, Fe(L1)6, and [Fe(CMe)(L1H)]PF7). The acid-base and redox properties of the amido complexes 2, 6, and their protio parent complexes 1, and 5 permit the determination of the p and bond dissociation free energy (BDFE) of their N-H bonds while the ligand scaffold is coordinated to metal centres of square planar and octahedral geometry, respectively. From relative concentrations obtained by the use of P{H} NMR spectroscopy, a p value of 14 is calculated for rhodium complex 1, 6.

Synthesis and Functionalisation of Superparamagnetic Nano-Rods towards the Treatment of Glioblastoma Brain Tumours.

The complete removal of glioblastoma brain tumours is impossible to achieve by surgery alone due to the complex finger-like tentacle structure of the tumour cells and their migration away from the bulk of the tumour at the time of surgery; furthermore, despite aggressive chemotherapy and radiotherapy treatments following surgery, tumour cells continue to grow, leading to the death of patients within 15 months after diagnosis. The naturally occurring carnosine dipeptide has previously demonstrated activity against in vitro cultured glioblastoma cells; however, at natural physiological concentrations, its activity is too low to have a significant effect. Towards realising the full oncological potential of carnosine, the dipeptide was embedded within an externally triggered carrier, comprising a novel nano rod-shaped superparamagnetic iron oxide nanoparticle (ca.

Trans Element-Hydrogen Bonds: A Distinctive Difference Between Transition Metals and Main Group Elements.

The change in sign of the interaction force constant between element-hydrogen stretching modes of -dihydrides of the d block and p block elements is analyzed for the first time. As the transition metal M approaches group 12, the higher energy symmetric -H-M-H vibration ν approaches the energy of the antisymmetric vibration ν. Crossing to group 13 elements E, the -H-E-H vibration ν increasingly drops below ν.

Atrophy Resistant vs. Atrophy Susceptible Skeletal Muscles: "aRaS" as a Novel Experimental Paradigm to Study the Mechanisms of Human Disuse Atrophy.

Objective: Disuse atrophy (DA) describes inactivity-induced skeletal muscle loss, through incompletely defined mechanisms. An intriguing observation is that individual muscles exhibit differing degrees of atrophy, despite exhibiting similar anatomical function/locations. We aimed to develop an innovative experimental paradigm to investigate Atrophy Resistant (TA) and Atrophy Susceptible (MG) muscles (aRaS) with a future view of uncovering central mechanisms.

Current Advances on the Regeneration of Musculoskeletal Interfaces.

The regeneration of the musculoskeletal system has been widely investigated. There is now detailed knowledge about the organs composing this system. Research has also investigated the zones between individual tissues where physical, mechanical, and biochemical properties transition.

Systematic Trends in the Electrochemical Properties of Transition Metal Hydride Complexes Discovered by Using the Ligand Acidity Constant Equation.

Understanding the thermodynamics of paramagnetic transition metal hydride complexes, especially of the abundant 3 metals, is important in the design of electrocatalysts and organometallic catalysts. The p([MHL]/[ML) of paramagnetic hydrides in MeCN are estimated for the first time using the ligand acidity constant (LAC) equation where contributions to the p from each ligand are simply added together, with the sum corrected for effects of charge and 5 metals. The p([MHL]/ML) of over 200 hydride complexes MHL are used, along with their electrochemical potentials from the literature, in an uncommonly applied thermochemical cycle in order to reveal systematic trends in the redox couples M and M (M = Cr, Mo, W), Mn, Re and Re, M and M (M = Fe, Ru, Os), and M and M (M = Co, Rh, and Ir) and allow the estimation of the bond dissociation free energies BDFE(MH) of the unoxidized hydrides MHL and the prediction of the electrochemical potential for their oxidation.

Crystal structure of bis-[(,)-1,2-(bi-naph-thyl-phospho-nito)ethane]-dichlorido-iron(II) di-chloro-methane disolvate.

In the title compound (systematic name: bis-{1,2-bis[12,14-dioxa-13-phospha-penta-cyclo-[13.8.0.

Advanced Sandwich Composite Cores for Patient Support in Advanced Clinical Imaging and Oncology Treatment.

Ongoing advances in both imaging and treatment for oncology purposes have seen a significant rise in the use of not only the individual imaging modalities, but also their combination in single systems such as Positron Emission Tomography combined with Computed Tomography (PET-CT) and PET-MRI (Magnetic Resonance Imaging) when planning for advanced oncology treatment, the most demanding of which is proton therapy. This has identified issues in the availability of suitable materials upon which to support the patient undergoing imaging and treatment owing to the differing requirements for each of the techniques. Sandwich composites are often selected to solve this issue but there is little information regarding optimum materials for their cores.

Using nature's blueprint to expand catalysis with Earth-abundant metals.

Numerous redox transformations that are essential to life are catalyzed by metalloenzymes that feature Earth-abundant metals. In contrast, platinum-group metals have been the cornerstone of many industrial catalytic reactions for decades, providing high activity, thermal stability, and tolerance to chemical poisons. We assert that nature's blueprint provides the fundamental principles for vastly expanding the use of abundant metals in catalysis.

A One-Step Preparation of Tetradentate Ligands with Nitrogen and Phosphorus Donors by Reductive Amination and Representative Iron Complexes.

The synthesis and use of the first examples of unsymmetrical, mixed phosphine donor tripodal NPP' ligands N(CHCHPR)(CHCHPPh) are presented. The ligands are synthesized via a convenient, one pot reductive amination using 2-(diphenylphosphino)ethylamine and various substituted phosphonium dimers in order to introduce mixed phosphine donors substituted with P/P', those being Ph/Cy (), Ph/Pr (), Ph/Bu (), Ph/-Tol (), and Ph/-Tol (). Additionally, we have developed the first known synthesis of a symmetrical tripodal NP ligand N(CHCHPBu) using bench safe ammonium acetate as the lone nitrogen source ().

Woven Natural Fibre Reinforced Composite Materials for Medical Imaging.

Repeatable patient positioning is key to minimising the burden on planning radiotherapy treatment. There are very few materials commercially available which are suitable for use in all common imaging and treatment modalities such as magnetic resonance imaging (MRI), X-Ray computed tomography (CT) and radiotherapy. In this article, we present several such materials based on woven natural fibres embedded in a range of different resin materials which are suitable for such applications.

Phosphine-free ruthenium NCN-ligand complexes and their use in catalytic CO hydrogenation.

This work investigates the hydrogenation of carbon dioxide to formate catalysed by the phosphine-free Ru complexes Ru(OtBu)(κ-NCN)(bpy) and RuH(OtBu)(κ-NCN)(bpy) (OtBu = tert-butoxide, κ-NCN = 1,3-di(2-methylpyridyl)-4,5-diphenyl-1H-imidazol-2-ylidene, where one pyridyl moiety is not coordinated to Ru, bpy = 4,4'-di-tert-butyl-2,2'-dipyridyl). A catalytic cycle is proposed for this reaction, supported by computational studies and the characterization of the hydride and the formate intermediates proposed to be involved. Modest catalytic turnovers are demonstrated at relatively low pressures and temperatures.