Revisiting the isolation and characterisation of Entamoeba histolytica lipopeptidophosphoglycan.

The parasite Entamoeba histolytica is the cause of amoebic dysentery and liver abscess in humans. On the protozoan cell surface, a variety of glycosylated molecules are involved in the interaction with the environment, such as attachment to the colonic mucus. One of these molecules is the lipopeptidophosphoglycan (LPPG), a complex surface component with antigenic properties. Its structure is only partly known, it is a glycosylphosphatidylinositol (GPI)-linked glycoprotein with a large amount of O-glycosylation. To date, the sequence of a core protein has not been identified. In this study, we further investigated this complex surface molecule aided by the availability of the monoclonal antibody EH5, which had been raised in our laboratory. We studied the extraction of LPPG in various solvent mixtures and discovered that 2-butanol saturated water was simple and superior to other solvents used in the past. The isolated LPPG was subjected to treatment with several proteases and the Ser/Thr specific cleavage agent scandium (III) trifluoromethanesulfonate (scandium triflate). The products were probed with antibody EH5 and the blots showed that the LPPG preparation was largely resistant to standard proteases, but could be cleaved by the scandium compound. These observations could point to the existence of a Ser- or Thr-rich core protein structure.

Scandium Ion-Promoted Electron-Transfer Disproportionation of 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO•) in Acetonitrile and Its Regeneration Induced by Water.

2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO•), a persistent nitronyl nitroxide radical, has been used for the detection and trapping of nitric oxide, as a redox mediator for batteries, for the activity estimation of antioxidants, and so on. However, there is no report on the reactivity of PTIO• in the presence of redox-inactive metal ions. In this study, it is demonstrated that the addition of scandium triflate, Sc(OTf)3 (OTf = OSO2CF3), to an acetonitrile (MeCN) solution of PTIO• resulted in an electron-transfer disproportionation to generate the corresponding cation (PTIO+) and anion (PTIO-), the latter of which is suggested to be stabilized by Sc3+ to form [(PTIO)Sc]2+. The decay of the absorption band at 361 nm due to PTIO•, monitored using a stopped-flow technique, obeyed second-order kinetics. The second-order rate constant for the disproportionation, thus determined, increased with increasing the Sc(OTf)3 concentration to reach a constant value. A drastic change in the cyclic voltammogram recorded for PTIO• in deaerated MeCN containing 0.10 M Bu4NClO4 was also observed upon addition of Sc(OTf)3, suggesting that the large positive shift of the one-electron reduction potential of PTIO• (equivalent to the one-electron oxidation potential of PTIO-) in the presence of Sc(OTf)3 may result in the disproportionation. When H2O was added to the PTIO•-Sc(OTf)3 system in deaerated MeCN, PTIO• was completely regenerated. It is suggested that the complex formation of Sc3+ with H2O may weaken the interaction between PTIO- and Sc3+, leading to electron-transfer comproportionation to regenerate PTIO•. The reversible disproportionation of PTIO• was also confirmed by electron paramagnetic resonance (EPR) spectroscopy.

Towards Clinical Development of Scandium Radioisotope Complexes for Use in Nuclear Medicine: Encouraging Prospects with the Chelator 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic Acid (DOTA) and Its Analogues.

Scandium (Sc) isotopes have recently attracted significant attention in the search for new radionuclides with potential uses in personalized medicine, especially in the treatment of specific cancer patient categories. In particular, Sc-43 and Sc-44, as positron emitters with a satisfactory half-life (3.9 and 4.0 h, respectively), are ideal for cancer diagnosis via Positron Emission Tomography (PET). On the other hand, Sc-47, as an emitter of beta particles and low gamma radiation, may be used as a therapeutic radionuclide, which also allows Single-Photon Emission Computed Tomography (SPECT) imaging. As these scandium isotopes follow the same biological pathway and chemical reactivity, they appear to fit perfectly into the "theranostic pair" concept. A step-by-step description, initiating from the moment of scandium isotope production and leading up to their preclinical and clinical trial applications, is presented. Recent developments related to the nuclear reactions selected and employed to produce the radionuclides Sc-43, Sc-44, and Sc-47, the chemical processing of these isotopes and the main target recovery methods are also included. Furthermore, the radiolabeling of the leading chelator, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), and its structural analogues with scandium is also discussed and the advantages and disadvantages of scandium complexation are evaluated. Finally, a review of the preclinical studies and clinical trials involving scandium, as well as future challenges for its clinical uses and applications, are presented.

[Level and health evaluation of rare earth elements in human blood and hair in the mining areas in Northwest Hubei].

OBJECTIVE: To investigate the content of rare earth elements(REs)in blood and hair of residents in a RE mining area in Northwest Hubei, and evaluate the impact of REs on the health status of local residents. METHODS: A total of 191 residents from the core area of RE mining areas and 186 residents from non RE mining areas, aged 20-69, were selected. The content of REs in the blood and hair of the survey subjects was measured using inductively coupled plasma mass spectrometry, and compared with existing literature values. At the same time, blood tests and questionnaire surveys will be conducted on the health status of residents to examine whether human RE enrichment can lead to endemic diseases. RESULTS: The average total content of REs in the blood of residents in the mining area was 60.22 ng/mL, which was 3.35 times that of the control area; The average total content of REs in hair was 1197.91 ng/g, which was 6.32 times higher than the control area. As age increasing, the abundance of REs in the blood and hair of both men and women in mining areas increased. The proportion of Yttrium and Scandium in the blood and hair were much higher than that in the soil. Compared to hair, Yttrium and Scandium were more easily enriched in the blood. There was no significant difference in the probability of fatty liver, hepatitis B, hypoglycemia, hypotension, hypertension and heart disease and the average life span between residents in RE mining areas and those in the control area. CONCLUSION: The high daily average dietary intake of REs in residents leads to a relatively large accumulation of REs in human blood and hair, but no significant and substantial human health damage has been found at present.

Record High 36 K Transition Temperature to the Superconducting State of Elemental Scandium at a Pressure of 260 GPa.

Elemental materials provide clean and fundamental platforms for studying superconductivity. However, the highest superconducting critical temperature (T_{c}) yet observed in elements has not exceeded 30 K. Discovering elemental superconductors with a higher T_{c} is one of the most fundamental and challenging tasks in condensed matter physics. In this study, by applying high pressure up to approximately 260 GPa, we demonstrate that the superconducting transition temperature of elemental scandium (Sc) can be increased to 36 K from the transport measurement, which is a record-high T_{c} for superconducting elements. The pressure dependence of T_{c} implies the occurrence of multiple phase transitions in Sc, which is in agreement with previous x-ray diffraction results. Optimization of T_{c} is achieved in the Sc-V phase, which can be attributed to the strong coupling between d electrons and moderate-frequency phonons, as suggested by our first-principles calculations. This study provides insights for exploring new high-T_{c} elemental metals.

A critical review of the occurrence of scandium and yttrium in mushrooms.

Scandium (Sc) and Yttrium (Y) along with the other rare earth elements (REE) are being increasingly extracted to meet the escalating demand for their use in modern high technology applications. Concern has been voiced that releases from this escalating usage may pollute environments, including the habitats of wild species of mushrooms, many of which are foraged and prized as foods. This review collates the scarce information on occurrence of these elements in wild mushrooms and also reviews soil substrate levels, including forested habitats. Sc and Y occurred at lower levels in mushrooms (<1.0-1000 µg kg-1 dw for Sc and<1.8-1500 µg kg-1 dw for Y) compared to the corresponding range for the sum of the lanthanides in the same species (16-8400 µg kg-1 dw). The reported species showed considerably more variation in Y contents than Sc which show a narrow median distribution range (20-40 µg kg-1 dw). Data allowing temporal examination was very limited but showed no increasing trend between the 1970s to 2019, nor were any geographical influences apparent. The study of the essentiality, toxicity or other effects of REE including Sc and Y at levels of current dietary intake are as yet undefined. High intake scenarios using the highest median concentrations of Sc and Y, resulted in daily intakes of 1.2 and 3.3 µg respectively from 300 g portions of mushroom meals. These could be considered as low unless future toxicological insights make these intake levels relevant.

Mechanism and Origin of Site Selectivity and Regioselectivity of Scandium-Catalyzed Benzylic C-H Alkylation of Tertiary Anilines with Alkenes.

Benzylic C(sp3)-H alkylation of tertiary anilines with alkenes by an anilido-oxazoline-ligated scandium alkyl catalyst was recently reported with C-H site selectivity and alkene-dependent regioselectivity. Revealing the mechanism and origin of selectivity is undoubtedly of great importance for understanding experimental observations and developing new reactions. Herein, density functional theory (DFT) calculations have been carried out on the model reaction of Sc-catalyzed benzylic C(sp3)-H alkylation of N,N-dimethyl-o-toluidine with allylbenzene. The reaction generally undergoes the generation of active species, alkene insertion, and protonation steps. The difference of the distortion energy of the aniline moiety in transition states, which is related to the ring size of the forming metallacycles, accounts for the site selectivity of C-H activation. Benzylic C(sp3)-H activation possessing less strained five-membered metallacycle compared to the ortho-C(sp2)-H and α-methyl C(sp3)-H activation results in benzylic C(sp3)-H alkylation observed experimentally. Both steric and electronic factors are responsible for the 1,2-insertion regioselectivity for alkyl-substituted alkenes, while electronic factors control the 2,1-insertion manner for vinylsilanes. The analysis of original alkene substrates further strengthens the understanding of the alkene-dependent regioselectivity. These results help us to obtain the mechanistic understanding and are expected to be conducive to the development of new C-H functionalization reactions.

Effects of Er: YAG, Er,Cr: YSGG, and Nd: YAG laser irradiation and adhesive systems on the immediate and long-term bond strength of dentin: a systematic review and meta-analysis.

At present, lasers are increasingly used in the oral clinical field, and research and applications in dental hard tissue treatment are also increasing. The effect of laser etching dentin on the bonding strength of composite resin reported in the literature is still inconclusive. The purpose of this review was to evaluate whether laser etching can improve the immediate and long-term bonding strength of dentin and investigate the effect of different types of adhesives on the bonding strength of dentin. Two reviewers performed a literature search up from January 2012 to November 2021 in four databases: MEDLINE (PubMed), Web of Science, EMBASE, and the Cochrane Library. A total of 25 studies were included in the meta-analysis. The Cochrane Collaboration Bias Risk Assessment tool was used to evaluate the quality of the included literature, and an analysis was carried out using Review Manager Software version 5.3. The aging bond strength of dentin after erbium (Er): yttrium aluminum garnet (YAG) laser treatment was significantly lower than that of dentin in the bur group (P < 0.00001). At the same time, the bond strength of dentin immediately and aging after (Er), chromium-doped (Cr): yttrium scandium gallium garnet (YSGG) laser treatment was lower than that of dentin in the bur group (P < 0.05). There was no significant difference in the immediate and aging bonding strength among samples in the Er: YAG laser, Er, Cr: YSGG laser, and blank control groups (no laser or bur). The aging bond strength of samples after neodymium-doped (Nd): YAG laser treatment was higher than that of samples in the blank control group (P < 0.05); in addition, the performance of self-etching adhesive was slightly better than that of acid etching adhesive. Regardless of the applied surface treatment and the adhesive employed, dentin after aging showed significant bond degradation (P < 0.05). There was high heterogeneity of bond strength between different groups, and the small number of studies and the contradictory results may be the main reasons for this outcome.

Reconfigurable Compute-In-Memory on Field-Programmable Ferroelectric Diodes.

The deluge of sensors and data generating devices has driven a paradigm shift in modern computing from arithmetic-logic centric to data-centric processing. Data-centric processing require innovations at the device level to enable novel compute-in-memory (CIM) operations. A key challenge in the construction of CIM architectures is the conflicting trade-off between the performance and their flexibility for various essential data operations. Here, we present a transistor-free CIM architecture that permits storage, search, and neural network operations on sub-50 nm thick Aluminum Scandium Nitride ferroelectric diodes (FeDs). Our circuit designs and devices can be directly integrated on top of Silicon microprocessors in a scalable process. By leveraging the field-programmability, nonvolatility, and nonlinearity of FeDs, search operations are demonstrated with a cell footprint <0.12 µm2 when projected onto 45 nm node technology. We further demonstrate neural network operations with 4-bit operation using FeDs. Our results highlight FeDs as candidates for efficient and multifunctional CIM platforms.

Water-Induced Regeneration of a 2,2-Diphenyl-1-picrylhydrazyl Radical after Its Scandium Ion-Promoted Electron-Transfer Disproportionation in an Aprotic Medium.

A neutral, stable radical, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), has been frequently used to estimate the activity of antioxidants for more than 60 years. However, the number of reports about the effect of metal ions on the reactivity of DPPH• is quite limited. We have recently reported a unique electron-transfer disproportionation of DPPH• to produce the DPPH cations (DPPH+) and anions (DPPH-) upon the addition of scandium triflate [Sc(OTf)3 (OTf = OSO2CF3)] to an acetonitrile (MeCN) solution of DPPH•. The driving force of this reaction is suggested to be an interaction between DPPH- and Sc3+. In this study, it is demonstrated that the addition of H2O to the DPPH•-Sc(OTf)3 system in MeCN resulted in an increase in the absorption band at 519 nm due to DPPH•. This indicated that an electron-transfer comproportionation occurred to regenerate DPPH•. The regeneration of DPPH• was also confirmed by electron paramagnetic resonance (EPR) spectroscopy. The amount of DPPH• increased with an increasing amount of added H2O to reach a constant value. The detailed mechanism of regeneration of DPPH• was proposed based on the detailed spectroscopic and kinetic analyses, in which the reaction of DPPH+ with [(DPPH)2Sc(H2O)3]+ generated upon the addition of H2O to [(DPPH)2Sc]+ is the rate-determining step.

Scandium Radioisotopes-Toward New Targets and Imaging Modalities.

The concept of theranostics uses radioisotopes of the same or chemically similar elements to label biological ligands in a way that allows the use of diagnostic and therapeutic radiation for a combined diagnosis and treatment regimen. For scandium, radioisotopes -43 and -44 can be used as diagnostic markers, while radioisotope scandium-47 can be used in the same configuration for targeted therapy. This work presents the latest achievements in the production and processing of radioisotopes and briefly characterizes solutions aimed at increasing the availability of these radioisotopes for research and clinical practice.

Accelerator-Based Production of Scandium Radioisotopes for Applications in Prostate Cancer: Toward Building a Pipeline for Rapid Development of Novel Theranostics.

In the field of nuclear medicine, the ß+ -emitting 43Sc and ß- -emitting 47Sc are promising candidates in cancer diagnosis and targeted radionuclide therapy (TRT) due to their favorable decay schema and shared pharmacokinetics as a true theranostic pair. Additionally, scandium is a group-3 transition metal (like 177Lu) and exhibits affinity for DOTA-based chelators, which have been studied in depth, making the barrier to implementation lower for 43/47Sc than for other proposed true theranostics. Before 43/47Sc can see widespread pre-clinical evaluation, however, an accessible production methodology must be established and each isotope's radiolabeling and animal imaging capabilities studied with a widely utilized tracer. As such, a simple means of converting an 18 MeV biomedical cyclotron to support solid targets and produce 43Sc via the 42Ca(d,n)43Sc reaction has been devised, exhibiting reasonable yields. The NatTi(γ,p)47Sc reaction is also investigated along with the successful implementation of chemical separation and purification methods for 43/47Sc. The conjugation of 43/47Sc with PSMA-617 at specific activities of up to 8.94 MBq/nmol and the subsequent imaging of LNCaP-ENZaR tumor xenografts in mouse models with both 43/47Sc-PSMA-617 are also presented.

Erbium, chromium:Yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser versus diode laser in the treatment of pericoronitis.

Background: There are limited number of studies about the lasers used for the treatment of pericoronitis infection. Aim: To compare the Er, Cr:YSGG laser and diode laser applications clinically in the treatment of pericoronitis infection. Patients and Methods: Sixty patients with pericoronitis infection were divided into three groups using block randomization: Er, Cr:YSGG + antibiotic group, n = 20 (mean age: 24.20 ± 6.13; 14 females, 6 males); diode group + antibiotic, n = 20 (mean age: 23.45 ± 2.96; 14 females, 6 males); and antibiotic, n = 20 (mean age: 22.45 ± 3.02; 11 females, 9 males). In addition, laser application was performed for patients in the Er, Cr:YSGG and diode laser groups on the 1st and 2nd days until the extraction day. Tooth extractions were performed on the 3rd day for all patients. Patients' pain (with visual analog scale [VAS]), lymphadenopathy, and local edema were clinically evaluated in the first 3 days and on the 7th day of treatment. Results: Pain score on the 2nd day of treatment was determined to be significantly lower in the Er, Cr:YSGG + antibiotic laser group as compared with the other two groups (P = 0.019). Although regression of lymphadenopathy on the 3rd day was highest (P = 0.025) in the Er, Cr:YSGG group, there was no significant difference between the groups regarding local edema. Conclusion: Er, Cr:YSGG laser improved the healing process in the treatment of pericoronitis and made an important contribution to the treatment.

Scandium-Catalyzed Skeleton Conversion of Lathyrane to Lathyranone-Type Euphorbia Diterpenes.

Naturally occurring 1(15 → 14)abeo-lathyrane rearrangement-type diterpene lathyranone A (1) was prepared from lathyrane-type Euphorbia factor L11 (1a) via an efficient Sc(OTf)3/Et2NH-catalyzed α-ketol rearrangement, which was also suitable for the synthesis of lathyranones 2 and 3. This skeletal conversion strategy had the characteristic of biogenetically patterned synthesis and provided a convenient method for accessing naturally rare functionalized lathyranones from lathyranes. Moreover, the absolute configuration of the lathyranone skeleton was confirmed for the first time by the X-ray diffraction of 2.

Ambident reactivity of 5-aminopyrazoles towards donor-acceptor cyclopropanes.

Lewis acid-catalysed reactions of donor-acceptor cyclopropanes with 1,3-disubstituted 5-aminopyrazoles were investigated. Under catalysis with gallium(III) chloride, products of the three-membered ring opening via a nucleophilic attack of the exocyclic amino group were obtained in a chemoselective manner. Oppositely, in the presence of scandium(III) triflate, products of either N-alkylation or C(4)-alkylation, or a mixture of both were formed. The products of the C(4) alkylation were transformed in one step into tetrahydropyrazolo[3,4-b]azepines that are attractive for medicinal chemistry and pharmacology.

Improvement of apical papilla cell attachment after erbium, chromium-doped yttrium, scandium, gallium, and garnet laser application: a study in an ex vivo immature tooth model.

The purposes of this study were (1) to investigate the direct effect of an Er,Cr:YSGG laser on human apical papilla cell (APC) proliferation and mineralization and (2) to examine the effect of Er,Cr:YSGG laser, when applied to an ex vivo immature tooth model, on APC attachment. An Er,Cr:YSGG laser at various power outputs (0.1, 0.5, and 1 W) was used at different positions (2, 5, or 8 mm from the cells) to irradiate cultured APCs. APC proliferation and mineralization were assessed at various intervals. For the cell attachment evaluation, ex vivo tooth models containing dentin samples were irrigated with either EDTA or normal saline solution (NSS) and supplemented with laser activation. Fibronectin-positive-staining cells were counted and analyzed. The number of APCs was significantly greater when power outputs of 0.1 W and 0.5 W were used than when 1 W was used (P < 0.05). The close contact of laser application, at 2 and 5 mm, exerted a negative effect on cell proliferation at 24 and 48 h. The application at 8 mm did not show the deterioration effect. APC mineralization was reduced after laser irradiation, regardless of the power and the tip positioning, at 21 days. APC attachment in all laser-activated groups was significantly greater than in the groups without laser. The use of Er,Cr:YSGG laser significantly promoted APC attachment on the root canal dentin.

Erbium, chromium-doped: yttrium, scandium, gallium, garnet and diode lasers in the treatment of peri-implantitis: clinical and biochemical outcomes in a randomized-controlled clinical trial.

This study aims to evaluate the effects of 940 nm diode laser and 2780 nm erbium, chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser used in addition to mechanical therapy in the non-surgical treatment of peri-implantitis on clinical parameters and matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in the peri-implant crevicular fluid. A total of 50 patients with peri-implantitis were randomized into three groups to receive peri-implant treatment. The control group (n = 17) only received conventional non-surgical mechanical therapy. The trial groups [(diode group (n = 16) and Er,Cr:YSGG group (n = 17)] received dental laser in addition to mechanical therapy. Gingival index (GI), plaque index (PI), bleeding on probing, probing depth (PD), MMP-9, and TIMP-1 levels were assessed at baseline (T0) and at 6 months after treatment (T1). The GI, PI, and PD significantly decreased in all groups at T1, compared to T0 (p < 0.05). The decrease in the PD was similar between the control and diode groups with Er,Cr:YSGG providing more reduction (1.16 ± 0.64 mm) than either method (p = 0.032). A significant intra-group decrease in MMP-9 level was only observed in the Er,Cr:YSGG group (p = 0.009). The decrease in TIMP-1 level from T0 to T1 was similar between the control and the diode groups (p > 0.05) and it was significantly lower than the decrease in the Er,Cr:YSGG group (p < 0.05). Addition of diode laser to non-surgical mechanical therapy does not provide any additional benefit for treatment outcomes. The Er,Cr:YSGG laser seems to be more efficient both at clinical and molecular levels. ClinicalTrials, ID: NCT04730687. Registered 13 April 2021. Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04730687.

Design and 3D FEM Analysis of a Flexible Piezoelectric Micromechanical Ultrasonic Transducer Based on Sc-Doped AlN Film.

In this paper, a flexible piezoelectric micromachined ultrasonic transducer (PMUT) based on Scandium (Sc)-doped Aluminum Nitride (AlN) film was designed and modeled by the three-dimensional finite element method (3D-FEM). The resonant frequency of 218.1 kHz was reported. It was noticeable that a high effective electromechanical coupling coefficient (k2eff) of 1.45% was obtained when a combination of a flexible PI and a thin Si layer was used as the PMUT supporting structure layer. Compared with a pure Si supporting layer counterpart, the coupling coefficient had been improved by 110.68%. Additionally, the increase of Sc doping concentration in AlN film further enhanced the device electromechanical coupling coefficient and resulted in an improvement for transmitting/receiving sensitivity of the proposed flexible PMUT. When the doping concentration of Sc reached 30%, the emission sensitivity was as large as 1.721 µm/V, which was 2.86 times greater than that of conventional AlN film-based PMUT. The receiving sensitivity was found to be 2.11 V/KPa, which was as high as 1.23 times the performance of an undoped device. Furthermore, the bending simulation result showed that the proposed flexible PMUT device can maintain a good mechanical stability when the bending radius is greater than 1.5 mm. The simulation of sound field characteristics demonstrated that the flexible PMUT based on AlScN could receive stable sound pressure signals under the bending radius of 1.5 cm.

Scandium Recovery from Aqueous Solution by Adsorption Processes in Low-Temperature-Activated Alumina Products.

In this paper, we studied the scandium adsorption from aqueous solutions on the surface of low-temperature-activated alumina products (GDAH). The GDAH samples are industrially manufactured, coming from the Bayer production cycle of the Sierra Leone bauxite as aluminium hydroxide, and further, by drying, milling, classifying and thermally treating up to dehydroxilated alumina products at low temperature. All experiments related to hydroxide aluminium activation were conducted at temperature values of 260, 300 and 400 °C on samples having the following particle sizes: <10 µm, 20 µm, <45 µm and <150 µm, respectively. The low-temperature-activated alumina products were characterised, and the results were published in our previous papers. In this paper, we studied the scandium adsorption process on the above materials and related thermodynamic and kinetic studies.

The Synthesis and Structure of a Scandium Nitrate Hydroxy-Bridged Dimeric Complex Supported by Bipyridyl Ligands.

The current discussion on whether scandium, yttrium and lanthanum should represent Group 3 in the Periodic Table or whether lutetium should replace lanthanum in the group has prompted us to further explore the structural chemistry of the Group 3 elements and compare the coordination numbers and coordination geometries adopted. The steric and electronic properties of the coordinated ligands have a major influence on the structures adopted. We report the synthesis and crystal structure determination of an unusual dinuclear scandium complex [(bipy)(NO3)2Sc(µ-OH)2Sc(NO3)2(bipy)] obtained by the reaction of hydrated scandium nitrate with 2,2'-bipyridyl (bipy) in either ethanol or nitromethane. The crystal structure of the complex shows that the scandium centers are eight coordinate, and the structure obtained contrasts with related complexes found in the lanthanide series [Ln(bipy)2(NO3)3] and [Ln(phen)2(NO3)3] (phen = phenanthroline) and in [M(terpy)(NO3)3] (M = Sc, Er-Lu), where these complexes are all mononuclear.