Variants in the degron of AFF3 are associated with intellectual disability, mesomelic dysplasia, horseshoe kidney, and epileptic encephalopathy.

The ALF transcription factor paralogs, AFF1, AFF2, AFF3, and AFF4, are components of the transcriptional super elongation complex that regulates expression of genes involved in neurogenesis and development. We describe an autosomal dominant disorder associated with de novo missense variants in the degron of AFF3, a nine amino acid sequence important for its binding to ubiquitin ligase, or with de novo deletions of this region. The sixteen affected individuals we identified, along with two previously reported individuals, present with a recognizable pattern of anomalies, which we named KINSSHIP syndrome (KI for horseshoe kidney, NS for Nievergelt/Savarirayan type of mesomelic dysplasia, S for seizures, H for hypertrichosis, I for intellectual disability, and P for pulmonary involvement), partially overlapping the AFF4-associated CHOPS syndrome. Whereas homozygous Aff3 knockout mice display skeletal anomalies, kidney defects, brain malformations, and neurological anomalies, knockin animals modeling one of the microdeletions and the most common of the missense variants identified in affected individuals presented with lower mesomelic limb deformities like KINSSHIP-affected individuals and early lethality, respectively. Overexpression of AFF3 in zebrafish resulted in body axis anomalies, providing some support for the pathological effect of increased amount of AFF3. The only partial phenotypic overlap of AFF3- and AFF4-associated syndromes and the previously published transcriptome analyses of ALF transcription factors suggest that these factors are not redundant and each contributes uniquely to proper development.

Organoid transduction using recombinant adeno-associated viral vectors: Challenges and opportunities.

Cellular 3D structures, for example, organoids, are an excellent model for studying and developing treatments for various diseases, including hereditary ones. Therefore, they are increasingly being used in biomedical research. From the point of view of safety and efficacy, recombinant adeno-associated viral (rAAV) vectors are currently most in demand for the delivery of various transgenes for gene replacement therapy or other applications. The delivery of transgenes using rAAV vectors to various types of organoids is an urgent task, however, it is associated with a number of problems that are discussed in this review. Cellular heterogeneity and specifics of cultivation of 3D structures determine the complexity of rAAV delivery and are sometimes associated with low transduction efficiency. This review surveys the main ways to solve emerging problems and increase the efficiency of transgene delivery using rAAVs to organoids. A clear understanding of the stage of development of the organoid, its cellular composition and the presence of surface receptors will allow obtaining high levels of organoid transduction with existing rAAV vectors.

Approaches to purification and concentration of rAAV vectors for gene therapy.

Recombinant adeno-associated viruses (rAAVs) are promising vectors for the delivery of various genetic constructs into eukaryotic cells. rAAVs have a number of properties that make it possible to successfully use them both in vitro and in vivo. Purification and concentration of rAAV vectors are critical for achieving high viral titer, stability, efficiency, and purity. This review systematically analyses all available purification approaches. The purification methods described in this work differ substantially from each other in mechanisms, efficiency, labor time, and cost. Researchers have to choose a purification algorithm depending on the purpose of their work. We strive to simplify the choice of the necessary and sufficient technique based on the experimental needs and available resources of the laboratory.

Synthesis, Structure, and Properties of a Copper(II) Binuclear Complex Based on Trifluoromethyl Containing Bis(pyrazolyl)hydrazone.

A new complex of copper(II) with methyl-5-(trifluoromethyl)pyrazol-3-yl-ketazine (H2L) was synthesized with the composition [Cu2L2]∙C2H5OH (1). Recrystallization of the sample from DMSO yielded a single crystal of the composition [Cu2L2((CH3)2SO)] (2). The coordination compounds were studied by single-crystal X-ray diffraction analysis, IR spectroscopy, and static magnetic susceptibility method. The data obtained indicate that the polydentate ligand is coordinated by both acyclic nitrogen and heterocyclic nitrogen atoms. The cytotoxic activity of the ligand and complex 1 was investigated on human cell lines MCF7 (breast adenocarcinoma), Hep2 (laryngeal carcinoma), A549 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MRC5 (non-tumor lung fibroblasts). The complex was shown to have a pronounced dose-dependent cytotoxicity towards these cell lines with LC50 values in the range of 0.18-4.03 µM.

Semiconducting Electronic Structure of the Ferromagnetic Spinel HgCr_{2}Se_{4} Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy.

We study the electronic structure of the ferromagnetic spinel HgCr_{2}Se_{4} by soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) and first-principles calculations. While a theoretical study has predicted that this material is a magnetic Weyl semimetal, SX-ARPES measurements give direct evidence for a semiconducting state in the ferromagnetic phase. Band calculations based on the density functional theory with hybrid functionals reproduce the experimentally determined band gap value, and the calculated band dispersion matches well with ARPES experiments. We conclude that the theoretical prediction of a Weyl semimetal state in HgCr_{2}Se_{4} underestimates the band gap, and this material is a ferromagnetic semiconductor.

Airway and Lung Organoids from Human-Induced Pluripotent Stem Cells Can Be Used to Assess CFTR Conductance.

Airway and lung organoids derived from human-induced pluripotent stem cells (hiPSCs) are current models for personalized drug screening, cell-cell interaction studies, and lung disease research. We analyzed the existing differentiation protocols and identified the optimal conditions for obtaining organoids. In this article, we describe a step-by-step protocol for differentiating hiPSCs into airway and lung organoids. We obtained airway and lung organoids from a healthy donor and from five donors with cystic fibrosis. Analysis of the cellular composition of airway and lung organoids showed that airway organoids contain proximal lung epithelial cells, while lung organoids contain both proximal and distal lung epithelial cells. Forskolin-induced swelling of organoids derived from a healthy donor showed that lung organoids, as well as airway organoids, contain functional epithelial cells and swell after 24 h exposure to forskolin, which makes it a suitable model for analyzing the cystic fibrosis transmembrane conductance regulator (CFTR) channel conductance in vitro. Thus, our results demonstrate the feasibility of generating and characterizing airway and lung organoids from hiPSCs, which can be used for a variety of future applications.

Bridging Gaps in HDR Improvement: The Role of MAD2L2, SCAI, and SCR7.

This study aimed to enhance homology-directed repair (HDR) efficiency in CRISPR/Cas-mediated genome editing by targeting three key factors regulating the balance between HDR and non-homologous end joining (NHEJ): MAD2L2, SCAI, and Ligase IV. In order to achieve this, a cellular model using mutated eGFP was designed to monitor HDR events. Results showed that MAD2L2 knockdown and SCR7 treatment significantly improved HDR efficiency during Cas9-mediated HDR repair of the mutated eGFP gene in the HEK293T cell line. Fusion protein Cas9-SCAI did not improve HDR. This study is the first to demonstrate that MAD2L2 knockdown during CRISPR-mediated gene editing in HEK293T cells can increase precise correction by up to 10.2 times. The study also confirmed a moderate but consistent effect of SCR7, an inhibitor of Ligase IV, which increased HDR by 1.7 times. These findings provide valuable insights into improving HDR-based genome editing efficiency.

Synthesis, Structure, and Magnetic and Biological Properties of Copper(II) Complexes with 1,3,4-Thiadiazole Derivatives.

New coordination compounds of copper(II) with 2,5-bis(ethylthio)-1,3,4-thiadiazole (L1) and 2,5-bis(pyridylmethylthio)-1,3,4-thiadiazole (L2) with compositions Cu(L1)2Br2, Cu(L1)(C2N3)2, Cu(L2)Cl2, and Cu(L2)Br2 were prepared. The complexes were identified and studied by CHN analysis, infrared (IR) spectroscopy, powder X-Ray diffraction (XRD), and static magnetic susceptibility. The crystal structures of Cu(II) complexes with L1 were determined. The structures of the coordination core of complexes Cu(L2)Cl2 and Cu(L2)Br2 were determined by Extended X-ray absorption fine structure (EXAFS) spectroscopy. Magnetization measurements have revealed various magnetic states in the studied complexes, ranging from an almost ideal paramagnet in Cu(L1)2Br2 to alternating-exchange antiferromagnetic chains in Cu(L1)(C2N3)2, where double dicyanamide bridges provide an unusually strong exchange interaction (J1/kB ≈ -23.5 K; J2/kB ≈ -20.2 K) between Cu(II) ions. The cytotoxic activity of copper(II) complexes with L2 was estimated on the human cell lines of breast adenocarcinoma (MCF-7) and hepatocellular carcinoma (HepG2).

Iridium Complexes with BIAN-Type Ligands: Synthesis, Structure and Redox Chemistry.

A series of iridium complexes with bis(diisopropylphenyl)iminoacenaphtene (dpp-bian) ligands, [Ir(cod)(dpp-bian)Cl] (1), [Ir(cod)(NO)(dpp-bian)](BF4)2 (2) and [Ir(cod)(dpp-bian)](BF4) (3), were prepared and characterized by spectroscopic techniques, elemental analysis, X-ray diffraction analysis and cyclic voltammetry (CV). The structures of 1-3 feature a square planar backbone consisting of two C = C π-bonds of 1,5-cyclooctadiene (cod) and two nitrogen atoms of dpp-bian supplemented with a chloride ion (for 1) or a NO group (for 2) to complete a square-pyramidal geometry. In the nitrosyl complex 2, the Ir-N-O group has a bent geometry (the angle is 125°). The CV data for 1 and 3 show two reversible waves between 0 and -1.6 V (vs. Ag/AgCl). Reversible oxidation was also found at E1/2 = 0.60 V for 1. Magnetochemical measurements for 2 in a range from 1.77 to 300 K revealed an increase in the magnetic moment with increasing temperature up to 1.2 µB (at 300 K). Nitrosyl complex 2 is unstable in solution and loses its NO group to yield [Ir(cod)(dpp-bian)](BF4) (3). A paramagnetic complex, [Ir(cod)(dpp-bian)](BF4)2 (4), was also detected in the solution of 2 as a result of its decomposition. The EPR spectrum of 4 in CH2Cl2 is described by the spin Hamiltonian H = gßHS with S = 1/2 and gxx = gyy = 2.393 and gzz = 1.88, which are characteristic of the low-spin 5d7-Ir(II) state. DFT calculations were carried out in order to rationalize the experimental results.

A Series of Metal-Organic Frameworks with 2,2'-Bipyridyl Derivatives: Synthesis vs. Structure Relationships, Adsorption, and Magnetic Studies.

Five new metal-organic frameworks based on Mn(II) and 2,2'-bithiophen-5,5'-dicarboxylate (btdc2-) with various chelating N-donor ligands (2,2'-bipyridyl = bpy; 5,5'-dimethyl-2,2'-bipyridyl = 5,5'-dmbpy; 4,4'-dimethyl-2,2'-bipyridyl = 4,4'-dmbpy) [Mn3(btdc)3(bpy)2]·4DMF, 1; [Mn3(btdc)3(5,5'-dmbpy)2]·5DMF, 2; [Mn(btdc)(4,4;-dmbpy)], 3; [Mn2(btdc)2(bpy)(dmf)]·0.5DMF, 4; [Mn2(btdc)2(5,5'-dmbpy)(dmf)]·DMF, 5 (dmf, DMF = N,N-dimethylformamide) have been synthesized, and their crystal structure has been established using single-crystal X-ray diffraction analysis (XRD). The chemical and phase purities of Compounds 1-3 have been confirmed via powder X-ray diffraction, thermogravimetric, and chemical analyses as well as IR spectroscopy. The influence of the bulkiness of the chelating N-donor ligand on the dimensionality and structure of the coordination polymer has been analyzed, and the decrease in the framework dimensionality, as well as the secondary building unit's nuclearity and connectivity, has been observed for bulkier ligands. For three-dimensional (3D) coordination polymer 1, the textural and gas adsorption properties have been studied, revealing noticeable ideal adsorbed solution theory (IAST) CO2/N2 and CO2/CO selectivity factors (31.0 at 273 K and 19.1 at 298 K and 25.7 at 273 K and 17.0 at 298 K, respectively, for the equimolar composition and the total pressure of 1 bar). Moreover, significant adsorption selectivity for binary C2-C1 hydrocarbons mixtures (33.4 and 24.9 for C2H6/CH4, 24.8 and 17.7 for C2H4/CH4, 29.3 and 19.1 for C2H2/CH4 at 273 K and 298 K, respectively, for the equimolar composition and the total pressure of 1 bar) has been observed, making it possible to separate on 1 natural, shale, and associated petroleum gas into valuable individual components. The ability of Compound 1 to separate benzene and cyclohexane in a vapor phase has also been analyzed based on the adsorption isotherms of individual components measured at 298 K. The preferable adsorption of C6H6 over C6H12 by 1 at high vapor pressures (VB/VCH = 1.36) can be explained by the existence of multiple van der Waals interactions between guest benzene molecules and the metal-organic host revealed by the XRD analysis of 1 immersed in pure benzene for several days (1≅2C6H6). Interestingly, at low vapor pressures, an inversed behavior of 1 with preferable adsorption of C6H12 over C6H6 (KCH/KB = 6.33) was observed; this is a very rare phenomenon. Moreover, magnetic properties (the temperature-dependent molar magnetic susceptibility, χp(T) and effective magnetic moments, µeff(T), as well as the field-dependent magnetization, M(H)) have been studied for Compounds 1-3, revealing paramagnetic behavior consistent with their crystal structure.

Off-target effects of base editors: what we know and how we can reduce it.

The recently discovered CRISPR-Cas9 modification, base editors (BEs), is considered as one of the most promising tools for correcting disease-causing mutations in humans, since it allows point substitutions to be edited without generating double-stranded DNA breaks, and, therefore, with a significant decrease in non-specific activity. Until recently, this method was considered the safest, but at the same time, it is quite effective. However, recent studies of non-specific activity of BEs revealed that some of them lead to the formation of a huge number of off-targets in both DNA and RNA, occurring due to the nature of the Cas9-fused proteins used. In this review article, we have considered and combined data from numerous studies about the most commonly used and more described in detail APOBEC-based BEs and Target-AID version of CBE, as well as ABE7 and ABE8 with their basic modifications into TadA to improve BEs' specificity. In our opinion, modern advances in molecular genetics make it possible to dramatically reduce the off-target activity of base editors due to introducing mutations into the domains of deaminases or inhibition of Cas9 by anti-CRISPR proteins, which returns BEs to the leading position in genome editing technologies.

Lung organoids: current strategies for generation and transplantation.

Lung diseases occupy a leading position in human morbidity and are the third leading cause of death. Often the chronic forms of these diseases do not respond to therapy, so that lung transplantation is the only treatment option. The development of cellular and biotechnologies offers a new solution-the use of lung organoids for transplantation in such patients. Here, we review types of lung organoids, methods of their production and characterization, and experimental works on transplantation in vivo. These results show the promise of work in this direction. Despite the current problems associated with a low degree of cell engraftment, immune response, and insufficient differentiation, we are confident that organoid transplantation will find it is clinical application.

Dysferlinopathies: Clinical and genetic variability.

Dysferlinopathies are a clinically heterogeneous group of diseases caused by mutations in the DYSF gene encoding the dysferlin protein. Dysferlin is mostly expressed in muscle tissues and is localized in the sarcolemma, where it performs its main function of resealing and maintaining of the integrity of the cell membrane. At least four forms of dysferlinopathies have been described: Miyoshi myopathy, limb-girdle muscular dystrophy type 2B, distal myopathy with anterior tibial onset, and isolated hyperCKemia. Here we review the clinical features of different forms of dysferlinopathies and attempt to identify genotype-phenotype correlations. Because of the great clinical variability and rarety of the disease and mutations little is known, how different phenotypes develop as a result of different mutations. However, missense mutations seem to induce more severe disease than LoF, which is typical for many muscle dystrophies. The role of several specific mutations and possible gene modifiers is also discussed in the paper.

Rational Design of ssODN to Correct Mutations by Gene Editing.

Gene editing allows to make a variety of targeted changes in genome, which can potentially be used to treat hereditary human diseases. Despite numerous studies in this area, effectiveness of gene editing methods for correcting mutations is still low, so these methods are not allowed in routine practice. It has been shown that rational design of genome editing components can significantly increase efficiency of mutation correction. In this work, we propose design of single-stranded oligodeoxyribonucleotides (ssODNs) to increase efficiency of gene editing. Using a model system to repair knocked out EGFP that is integrated into the genome of HEK293T cell culture, we have shown that only a small part of ssODN (about 20 nucleotides: from the 15th nucleotide at 3'-end to the 4th nucleotide at 5'-end), a donor molecule for repairing double-stranded DNA breaks, is integrated into the site of the break. Based on the obtained data, it is possible to rationally approach the design of ssODNs to correct mutations using CRISPR-Cas9 method for the development of gene therapy for hereditary human diseases.

Improving Homology-Directed Repair in Genome Editing Experiments by Influencing the Cell Cycle.

Genome editing is currently widely used in biomedical research; however, the use of this method in the clinic is still limited because of its low efficiency and possible side effects. Moreover, the correction of mutations that cause diseases in humans seems to be extremely important and promising. Numerous attempts to improve the efficiency of homology-directed repair-mediated correction of mutations in mammalian cells have focused on influencing the cell cycle. Homology-directed repair is known to occur only in the late S and G2 phases of the cell cycle, so researchers are looking for safe ways to enrich the cell culture with cells in these phases of the cell cycle. This review surveys the main approaches to influencing the cell cycle in genome editing experiments (predominantly using Cas9), for example, the use of cell cycle synchronizers, mitogens, substances that affect cyclin-dependent kinases, hypothermia, inhibition of p53, etc. Despite the fact that all these approaches have a reversible effect on the cell cycle, it is necessary to use them with caution, since cells during the arrest of the cell cycle can accumulate mutations, which can potentially lead to their malignant transformation.

Complex Diagnostics of Non-Specific Intellectual Developmental Disorder.

Intellectual development disorder (IDD) is characterized by a general deficit in intellectual and adaptive functioning. In recent years, there has been a growing interest in studying the genetic structure of IDD. Of particular difficulty are patients with non-specific IDD, for whom it is impossible to establish a clinical diagnosis without complex genetic diagnostics. We examined 198 patients with non-specific IDD from 171 families using whole-exome sequencing and chromosome microarray analysis. Hereditary forms of IDD account for at least 35.7% of non-specific IDD, of which 26.9% are monogenic forms. Variants in the genes associated with the BAF (SWI/SNF) complex were the most frequently identified. We were unable to identify phenotypic features that would allow differential diagnosis of monogenic and microstructural chromosomal rearrangements in non-specific IDD at the stage of clinical examination, but due to its higher efficiency, exome sequencing should be the diagnostic method of the highest priority study after the standard examination of patients with NIDD in Russia.

Structure and Properties of Heterometallics Based on Lanthanides and Transition Metals with Methoxy-ß-Diketonates.

The possibility of obtaining volatile polynuclear heterometallic complexes containing lanthanides and transition metals bound by methoxy-ß-diketonates was studied. New compounds were prepared by cocrystallization of monometallic complexes from organic solvents. Ln(tmhd)3 were used as initial monometallic complexes (Ln = La, Pr, Sm, Gd, Tb, Dy, Lu; tmhd = 2,2,6,6-tetramethylheptane-3,5-dionate) in combination with TML2 in various ratios (TM = Cu, Co, Ni, Mn; L: L1 = 1,1,1-trifluoro-5,5-dimethoxypentane-2,4-dionate, L2 = 1,1,1-trifluoro-5,5-dimethoxy-hexane-2,4-dionate, L3 = 1,1,1-trifluoro-5-methoxy-5-methylhexane-2,4-dionate). Heterometallic complexes of the composition [(LnL2tmhd)2TM(tmhd)2] were isolated for light lanthanides Ln= La, Pr, Sm, Gd, and L= L1 or L2. By single crystal XRD, it has been established that heterometallic compounds containing La, Pr, Cu, Co, and Ni are isostructural linear coordination polymers of alternating mononuclear transition metal complexes and binuclear heteroleptic lanthanide complexes, connected by donor-acceptor interactions between oxygen atoms of the methoxy groups and transition metal atoms. A comparison of powder XRD patterns has shown that all heterometallic complexes obtained are isostructural. Havier lanthanides Ln = Tb, Dy, Lu did not form heterometallics. Instead, homometallic complexes Ln(L3)3 were identified for Ln = Dy, Lu as well as for Ln = La. The thermal properties of the complexes were investigated by TG-DTA and vacuum sublimation tests. The heterometallic complexes were found to be not volatile and decomposed under heating to produce inorganic composites of TM oxides and Ln fluorides. In contrast, Ln(L3)3 is volatile and may be sublimed in a vacuum. Results of magnetic measurements are discussed for several heterometallic and homometallic complexes.

Novel Copper(II) Complexes with Dipinodiazafluorene Ligands: Synthesis, Structure, Magnetic and Catalytic Properties.

The reactions of CuX2 (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuX2L1]2 (X = Cl (1), Br (2), L1 = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b']diquinolin-12(2H)-one) and [(CuX2)2L2]n (X = Cl (3), Br (4), L2 = (1R,3R,8R,10R,1'R,3'R,8'R,10'R)-2,2,2',2',9,9,9',9'-Octamethyl-1,1',2,2',3,3',4,4',7,7',8,8',9,9',10,10'-hexadecahydro-1,3:1',3':8,10:8',10'-tetramethano-12,12'-bi(cyclopenta [1,2-b:5,4-b']diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds 1, 2 and 4 were determined by X-ray diffraction (XRD) analysis. Complexes 1-2 have a monomeric structure, while complex 4 has a polymeric structure due to additional coordinating N,N sites in L2. All complexes contain a binuclear fragment {Cu2(µ-X)2×2} (X = Cl, Br) in their structures. Each copper atom has a distorted square-pyramidal coordination environment formed by two nitrogen atoms and three halogen atoms. The Cu-Nax distance is elongated compared to Cu-Neq. The EPR spectra of compounds 1-4 in CH3CN confirm their paramagnetic nature due to the d9 electronic configuration of the copper(II) ion. The magnetic properties of all compounds were studied by the method of static magnetic susceptibility. For complexes 1 and 2, the effective magnetic moments are µeff ≈ 1.87 and 1.83 µB (per each Cu2+ ion), respectively, in the temperature range 50-300 K, which are close to the theoretical spin value (1.73 µB). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu2(µ-X)2X2} (X = Cl, Br) dimers (J/kB ≈ 25 and 31 K for 1 and 2, respectively) or between dimers (θ' ≈ 0.30 and 0.47 K for 1 and 2, respectively) were found at low temperatures. For compounds 3 and 4, the magnetic susceptibility is well described by the Curie-Weiss law in the temperature range 1.77-300 K with µeff ≈ 1.72 and 1.70 µB for 3 and 4, respectively, and weak antiferromagnetic interactions (θ ≈ -0.4 K for 3 and -0.65 K for 4). Complexes 1-4 exhibit high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The maximum yield of cyclohexane oxidation products reached 50% (complex 3). Based on the data on the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play a decisive role in the oxidation reaction. The initial products in reactions with alkanes are alkyl hydroperoxides.

Biallelic variants in TMEM222 cause a new autosomal recessive neurodevelopmental disorder.

PURPOSE: To elucidate the novel molecular cause in families with a new autosomal recessive neurodevelopmental disorder. METHODS: A combination of exome sequencing and gene matching tools was used to identify pathogenic variants in 17 individuals. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and subcellular localization studies were used to characterize gene expression profile and localization. RESULTS: Biallelic variants in the TMEM222 gene were identified in 17 individuals from nine unrelated families, presenting with intellectual disability and variable other features, such as aggressive behavior, shy character, body tremors, decreased muscle mass in the lower extremities, and mild hypotonia. We found relatively high TMEM222 expression levels in the human brain, especially in the parietal and occipital cortex. Additionally, subcellular localization analysis in human neurons derived from induced pluripotent stem cells (iPSCs) revealed that TMEM222 localizes to early endosomes in the synapses of mature iPSC-derived neurons. CONCLUSION: Our findings support a role for TMEM222 in brain development and function and adds variants in the gene TMEM222 as a novel underlying cause of an autosomal recessive neurodevelopmental disorder.

Vanadium O-Centered Selenoiodide Complex: Synthesis and Structure of V4O(Se2)4I6·I2.

The first vanadium selenoiodide V4O(Se2)4I6·I2 was synthesized at a moderate temperature of 220 °C from V, Se, I2, and water. Its crystal structure (tetragonal space group P42/nbc, a = 11.838(1) Å, c = 18.689(1) Å) contains O-centered vanadium(IV) tetranuclear fragment [V4(µ4-O)(µ2-Se2)4(µ2-I)2I4], where the edges of the distorted tetrahedron V4 are bridged by four diselenide (Se2)2- and two iodide ligands; four terminal iodides coordinate V atoms additionally. This type of complex is known for Ti, Nb, and Ta but is new for vanadium. Magnetic susceptibility measurements of V4O(Se2)4I6·I2 showed four unpaired electrons on vanadium atoms at room temperature and drop of the effective magnetic moment at cool down, presumably due to partial electron pairing. Probability of this transition to the diamagnetic state is in accord with the calculated electronic structure.