Snowfall decrease in recent years undermines glacier health and meltwater resources in the Northwestern Pamirs.

Central Asia hosts some of the world's last relatively healthy mountain glaciers and is heavily dependent on snow and ice melt for downstream water supply, though the causes of this stable glacier state are not known. We combine recent in-situ observations, climate reanalysis and remote sensing data to force a land-surface model to reconstruct glacier changes over the last two decades (1999-2023) and disentangle their causes over a benchmark glacierized catchment in Tajikistan. We show that snowfall and snow depth have been substantially lower since 2018, leading to a decline in glacier health and reduced runoff generation.

Molecular and Electronic Structural Studies of - and - MR Complexes (M = Mo, Ru; R = CH, CHCMe): On the Interplay of Metal-Metal Bond Order and MR Pyramidalization.

Hexakis(neopentyl)diruthenium(III,III) [Ru(CHCMe) or RuNp], first synthesized in 1984, is a analogue of the classic MX Chisholm-type, unsupported metal-metal triply-bonded Group 6 complexes. We report an alternative synthetic route to RuNp and an updated low-temperature crystal structure. The Ru-Ru bond length (2.

Thin and ephemeral snow shapes melt and runoff dynamics in the Peruvian Andes.

The snow and glaciers of the Peruvian Andes provide vital water supplies in a region facing water scarcity and substantial glacier change. However, there remains a lack of understanding of snow processes and quantification of the contribution of melt to runoff. Here we apply a distributed glacio-hydrological model over the Rio Santa basin to disentangle the role of the cryosphere in the Andean water cycle.

PuCl{CoCp[OP(OEt)]}: transuranic elements entering the field of heterometallic molecular chemistry.

Recent advances enabled the discovery of heterometallic molecules for many metals: main group, d-block, lanthanides, and some actinides (U, Th). These complexes have at least two different metals joined by bridging ligands or by direct metal-metal bonding interactions. They are attractive because they can enable chemical cooperativity between metals from different parts of the periodic table.

Intermolecular C-H silylations of arenes and heteroarenes with mono-, bis-, and tris(trimethylsiloxy)hydrosilanes: control of silane redistribution under operationally diverse approaches.

Efficient catalytic protocols for C-H silylations of arenes and heteroarenes with sterically and electronically different hydrosiloxysilanes are disclosed. The silylations are catalyzed by a well-defined Rh-complex (1 mol%), derived from [Rh(1,5-hexadiene)Cl] and a bulky BINAP type ligand. This catalyst not only promotes C-Si bond formation affording the desired products in up to 95% isolated yield, but also can suppress the silane redistribution side reactions of HSiMe(OTMS).

Insight into the nature of carbon-metal bonding for -heterocyclic carbenes in gold/silver complexes and nanoparticles using DFT-correlated Raman spectroscopy: strong evidence for π-backbonding.

-Heterocyclic carbenes (NHCs) have emerged as promising ligands for stabilizing metallic complexes, nanoclusters, nanoparticles (NPs) and surfaces. The carbon-metal bond between NHCs and metal atoms plays a crucial role in determining the resulting material's stability, reactivity, function, and electronic properties. Using Raman spectroscopy coupled with density functional theory calculations, we investigate the nature of carbon-metal bonding in NHC-silver and NHC-gold complexes as well as their corresponding NPs.

Molybdenum(III) Amidinate: Synthesis, Characterization, and Vapor Phase Growth of Mo-Based Materials.

The synthesis, characterization, and thermogravimetric analysis of tris(,'-di-isopropylacetamidinate)molybdenum(III), Mo(iPr-AMD), are reported. Mo(iPr-AMD) is a rare example of a homoleptic mononuclear complex of molybdenum(III) and fills a longstanding gap in the literature of transition metal(III) trisamidinate complexes. Thermogravimetric analysis (TGA) reveals excellent volatilization at elevated temperatures, pointing to potential applications as a vapor phase precursor for higher temperature atomic layer deposition (ALD), or chemical vapor deposition (CVD) growth of Mo-based materials.

Electronic Structure of Re(OCR)Cl Complexes (R = H, CMe) and Reassignment of the Electronic Absorption Spectrum of Re(OCCMe)Cl.

Electronic structure calculations on two dinuclear rhenium(III) carboxylate complexes, Re(OCH)Cl and Re(OCCMe)Cl, are presented and discussed. Allowed electronic transitions for both molecules were calculated using time-dependent density functional theory (TDDFT). The results for the pivalate dimer, Re(OCCMe)Cl, are compared with previously reported single-crystal polarized absorption spectra obtained by Martin and co-workers (Inorg.

Total Synthesis of Polysubstituted γ-Butyrolactone Lignans (-)-Hinokinin, (-)-Bicubebin B, and (-)-Isodeoxypodophyllotoxin via Oxime Carbonate Formation.

The diverse structures and profound biological activities of lignan natural products have enticed significant effort in the exploration of new methodologies for their total synthesis. We have prepared γ-butyrolactone oximes from readily available δ-nitro alcohols via BocO mediated cyclization. The mild conditions are compatible with a wide range of functional groups, and this methodology has been applied to the total synthesis of five lignan natural products.

Warming-induced monsoon precipitation phase change intensifies glacier mass loss in the southeastern Tibetan Plateau.

Glaciers are key components of the mountain water towers of Asia and are vital for downstream domestic, agricultural, and industrial uses. The glacier mass loss rate over the southeastern Tibetan Plateau is among the highest in Asia and has accelerated in recent decades. This acceleration has been attributed to increased warming, but the mechanisms behind these glaciers' high sensitivity to warming remain unclear, while the influence of changes in precipitation over the past decades is poorly quantified.

Synthesis, characterization, X-ray and electronic structures of diethyl ether and 1,2-dimethoxyethane adducts of molybdenum(IV) chloride and tungsten(IV) chloride.

The bis(diethyl ether) and 1,2-dimethoxyethane (dme) adducts of molybdenum(IV) chloride and tungsten(IV) chloride are valuable starting materials for a variety of synthetic inorganic and organometallic reactions. Despite the broad utility and extensive use of these 6-coordinate complexes, their syntheses remain unoptimized, and their characterization incomplete after more than three decades. While exploring the ligand exchange behaviour of -MoCl(OEt), we obtained single crystals of this red-orange complex and subsequently compared its structural parameters with those of the recently reported -WCl(OEt).

"MoCl(dme)" Revisited: Improved Synthesis, Characterization, and X-ray and Electronic Structures.

"MoCl(dme)" (dme = 1,2-dimethoxyethane) is an important precursor for midvalent molybdenum chemistry, particularly for triply Mo-Mo bonded compounds of the type MoX (X = bulky anionic ligand). However, its exact structural identity has been obscure for more than 50 years. In search of a convenient, large-scale synthesis, we have found that -MoCl(EtO) dissolved in dme can be cleanly reduced with dimethylphenylsilane, MePhSiH, to provide khaki MoCl(dme) in ∼90% yield.

A 35-year-old mystery solved: a facile synthetic route and structural confirmation of tetrachlorobis(diethyl ether)tungsten(IV).

The true identity of the diethyl ether adduct of tungsten(IV) chloride, WCl(EtO), has been in doubt since 1985. Initially postulated as the bis-adduct, WCl(EtO), questions arose when elemental analyses were more in line with a mono-ether adduct, viz. WCl(EtO).

Ce-Si Mixed Oxide: A High Sulfur Resistant Catalyst in the NH-SCR Reaction through the Mechanism-Enhanced Process.

Investigating catalytic reaction mechanisms could help guide the design of catalysts. Here, aimed at improving both the catalytic performance and SO resistance ability of catalysts in the selective reduction of NO by NH (NH-SCR), an innovative CeO-SiO mixed oxide catalyst (CeSi2) was developed based on our understanding of both the sulfur poisoning and reaction mechanisms, which exhibited excellent SO/HO resistance ability even in the harsh working conditions (containing 500 ppm of SO and 5% HO). The strong interaction between Ce and Si (Ce-O-Si) and the abundant surface hydroxyl groups on CeSi2 not only provided fruitful surface acid sites but also significantly inhibited SO adsorption.

Crystal structure and Hirshfeld surface analysis of the elusive trichlorobis(diethyl ether)oxomolybdenum(V).

First reported in 1930, MoClO(EtO) is a by-product of the reductive synthesis of MoCl(OEt) from MoCl. We report herein the X-ray crystal structure and Hirshfeld surface characteristics of mer-MoClO(EtO), or [MoClO(CHO)]. The compound crystallizes in the orthorhombic space group P222.

A Combined Mechanochemical and Calcination Route to Mixed Cobalt Oxides for the Selective Catalytic Reduction of Nitrophenols.

Para-, or 4-nitrophenol, and related nitroaromatics are broadly used compounds in industrial processes and as a result are among the most common anthropogenic pollutants in aqueous industrial effluent; this requires development of practical remediation strategies. Their catalytic reduction to the less toxic and synthetically desirable aminophenols is one strategy. However, to date, the majority of work focuses on catalysts based on precisely tailored, and often noble metal-based nanoparticles.

Mechanochemical routes for the synthesis of acetyl- and bis-(imino)pyridine ligands and organometallics.

Organometallic precatalysts play a pivotal role in organic synthesis. However, their preparation often relies on multiple time, energy, and solvent intensive steps, including the synthesis of supporting organic ligand structures, and finally installation on the desired metal centres. We report the sustainable mechanochemical synthesis of acetyl- and bis-(imino)pyridine pincer complexes, a ubiquitous ligand class for organometallic precatalysts.