TNFRSF10B is involved in motor dysfunction in Parkinson's disease by regulating exosomal α-synuclein secretion from microglia.

A-synuclein (α-syn) is a protein associated with the pathogenesis of Parkinson's disease (PD), a neurodegenerative disease with no effective treatment. Therefore, there has been a strong drive to clarify the pathology of PD associated with α-syn. Several mechanisms have been proposed to unravel the pathological cascade of this disease, and most of them share a particular similarity: cell-to-cell communication through exosomes (EXO). Here, we show that tumor necrosis factor receptor superfamily member 10B (TNFRSF10B) promotes the secretion of α-syn-containing EXO by microglia, resulting in motor dysfunction in PD. Upregulation of TNFRSF10B predicted severer condition in PD patients. In response to α-syn preformed fibrils (PFF), the expression of TNFRSF10B was increased in microglia. PFF-treated microglia exhibited a pro-inflammatory phenotype and caused neuronal damage by secreting α-syn-containing EXO. TNFRSF10B downregulation in microglia inhibited the secretion of α-syn-containing EXO and the release of pro-inflammatory factors, and ameliorated neuronal injury. PFF induced motor dysfunction in mice, which was ameliorated by inhibiting TNFRSF10B to suppress microglia-mediated α-syn communication or by directly depleting microglia. Taken together, these results indicate that TNFRSF10B promotes neuronal injury and motor dysfunction by delivery of α-syn-containing EXO and highlight the TNFRSF10B knockdown as a potential therapeutic target in PD.

Risk factors for delirium after surgery for craniocerebral injury in the neurosurgical intensive care unit.

BACKGROUND: Postoperative delirium is common in patients who undergo neurosurgery for craniocerebral injury. However, there is no specific medical test to predict postoperative delirium to date. AIM: To explore risk factors for postoperative delirium in patients with craniocerebral injury in the neurosurgery intensive care unit (ICU). METHODS: A retrospective analysis was performed in 120 patients with craniocerebral injury admitted to Hainan People's Hospital/Hainan Hospital Affiliated to Hainan Medical University, The First Affiliated Hospital of Hainan Medical University, and The Second Affiliated Hospital of Hainan Medical University between January 2018 and January 2020. The patients were categorized into groups based on whether delirium occurred. Of them, 25 patients with delirium were included in the delirium group, and 95 patients without delirium were included in the observation group. Logistic regression analysis was used to explore the association between sex, age, educational level, Glasgow coma scale (GCS), complications (with or without concussion, cerebral contusion, hypoxemia and ventricular compression) and site of injury and delirium. RESULTS: The GCS score above 8 and concomitant disease of cerebral concussion, cerebral contusion, hypoxemia and ventricular compression, and damage to the frontal lobe were associated with delirium in patients admitted to neurosurgical intensive care unit (ICU) (all P < 0.05). However, age, sex, administration more than three medicines, and educational level were not significantly associated with the onset of delirium in patients with craniocerebral injury in the neurosurgical ICU (P < 0.05). Multivariate logistic regression analysis showed that GCS score above 8, cerebral concussion, cerebral contusion, hypoxemia, ventricle compression, and frontal lobe disorders were independent risk factors for delirium in patients with craniocerebral injury in the neurosurgical ICU (P < 0.05). CONCLUSION: GCS score, concussive concussion, cerebral contusion, hypoxemia, ventricle compression, and damage to frontal lobe are risk factors of postoperative delirium.

Clinical efficacy and safety of vitamin C in the treatment of septic shock patients: systematic review and meta-analysis.

BACKGROUND: Vitamin C deficiency is common in sepsis patients and is related to disease severity. At present, sepsis still has a high incidence and fatality rate. In sepsis, the body may develop microcirculation disorders and even develop organ failure. Exogenous vitamin C supplementation may be one of the effective adjuvant treatment measures for sepsis, which can not only improve the microcirculation of the body, but also affect the prognosis of patients by participating in the synthesis of norepinephrine, improving peripheral vascular resistance and increasing perfusion pressure. The efficacy and safety of vitamin C adjuvant therapy for septic shock are inconsistent in many studies, so it is very important to systematically evaluate the adjuvant effect of intravenous vitamin C in the treatment of septic shock. METHODS: Literature search of PubMed, EMBASE, The Cochrane Library, Web of Science, Wanfang, China Biology Medicine (CBM), and China National Knowledge Infrastructure (CNKI) electronic databases for vitamin C data since August 2021 for the treatment of patients with sepsis and septic shock. After screening, data extraction and quality evaluation were performed according to inclusion criteria, and meta-analysis was conducted using RevMan 5.3. RESULTS: The final 13 studies comprised 6 cohort studies and 7 randomized controlled trials (RCTs), with a total of 1,423 patients enrolled. Meta-analysis showed no significant effect of intravenous vitamin C on reducing in-hospital mortality rate [odds ratio (OR) =0.91, 95% confidence interval (CI): 0.76-1.08, P=0.27], intensive care unit (ICU) mortality rate (OR =0.84, 95% CI: 0.69-1.01, P=0.07), ICU stay (OR =0.88, 95% CI: 0.72-1.08, P=0.23) or total stay (OR =0.91, 95% CI: 0.68-1.21, P=0.51) in sepsis patients, nor did it improve the 72-h sequential organ failure assessment (72-h SOFA) score (OR =0.95, 95% CI: 0.77-1.18, P=0.66). DISCUSSION: Intravenous vitamin C showed no efficacy in the treatment of sepsis.

Effect of traditional Chinese medicine on serum inflammation and efficacy in patients with sepsis: a systematic review and meta-analysis.

BACKGROUND: Sepsis is a systemic infectious inflammatory response syndrome, which can release a large number of inflammatory mediators in serum, resulting in organ dysfunction. This study conducted a systematic review and meta-analysis of the reports of traditional Chinese medicine (TCM) in the treatment of sepsis in recent years, providing evidence for clinical diagnosis and treatment. METHODS: The databases of PubMed, Chinese Medical Literature (CBM), China National Knowledge Infrastructure (CNKI), Medline, and Web of Science were searched for clinical randomized controlled trials (RCTs) related to "Chinese traditional medicine" and "Sepsis" published from January 2015 to August 2021. After screening qualified articles, RevMan 5.4 software was used to evaluate the bias of included studies and perform meta-analysis. RESULTS: Finally, 8 articles were retrieved and screened, and a total of 862 patients entered the study. The results of meta-analysis showed that serum interleukin-6 (IL-6) levels were lower in sepsis patients after TCM treatment [mean difference (MD) =-20.70; 95% confidence interval (CI): -33.68 to -7.73; P=0.002]; tumor necrosis factor-α (TNF-α) levels were lower (MD =-4.17; 95% CI: -5.98 to -2.37; P<0.00001); acute physiological assessment and chronic health evaluation (APACHE) II scores were lower (MD =-2.92; 95% CI: -3.50 to -2.35; P<0.00001); mortality was lower [odds ratio (OR) =0.49; 95% CI: 0.33 to 0.74; P=0.0006]; and effective rate was higher (OR =3.43; 95% CI: 1.72 to 6.85; P=0.0005). DISCUSSION: On the basis of traditional western medicine treatment of sepsis, the addition of TCM treatment can effectively reduce the serum inflammatory response, improve the patient's immunity, and improve treatment efficacy.

Dodenuclear [Mn(III)(8)Ln(III)(4)] clusters with 2-(hydroxymethyl)pyridine: syntheses, structures, and magnetic properties.

A new family of isostructural Mn/Ln dodenuclear clusters: [Mn8Ln4(O)8(hmp)4(O2CPh)12(NO3)4(PhCO2H)(C2H5OH)] [Ln = La (1), Pr (2), Nd (3), Gd (4), Dy(5), hmpH = 2-(hydroxymethyl)pyridine] have been synthesized by the reaction of Mn(NO3)2 and Ln(NO3)3·6H2O with hmpH and benzoic acid as co-ligands. Compounds 1-5 possess a spindle-shaped core of [MnLn(µ4-O)4(µ3-O)4(µ3-OR)2(µ2-OR)8](10+), which is composed of six face-sharing defected cubane units and two square-pyramidal units. The compounds represent the highest nuclearity Mn/Ln clusters with the use of hmpH to date. That the ferromagnetic interactions dominated within complexes 1-4 were suggested by solid-state dc magnetic susceptibility analyses. Compound 4 displays a magnetic-caloric effect (MCE) with 13.94 J kg(-1) K(-1) as the entropy change at 6 K for ΔH = 8 T. Compounds 1 and 5 exhibit an out-of-phase χ''M peak maximum above 2.0 K. Fitting of the ac susceptibility data to an Arrhenius law gives an energy barrier Ueff = 6.88/7.44 K for compounds 1 and 5 respectively.

A family of novel Mn3Ln4 clusters displaying single-molecule magnet behavior.

Using 3-methyloxysalicylaldoxime (mosaoH2) and N-methyl diethanolamine (N-mdeaH2) as coligands, a family of heptanuclear Mn/Ln heterometallic compounds [Mn(II)Mn(III)2Ln(III)4(mosao)2(mosaoH)4(piv)4(N-mdea)4]·xMeCN [Ln = Dy(1), Tb(2) and Y(3), pivH = pivalic acid] have been prepared. The crystal structures of 1-3 were obtained, and their core consists of two Mn(III)Ln2(µ3-OR)2 (RO(2-) = N-mdea(2-)) triangles linked to a central Mn(II) atom. A dc magnetic susceptibility study reveals that single-ion effects of the Ln ions are dominant in compounds 1 and 2. As for compound 3, which contains diamagnetic Y ions, the magnetic interactions between Mn ions via oximate NO bridges are revealed to be ferromagnetic. Fitting of the χ(m)T vs. T data gives g = 1.96 and J = 1.12 cm(-1), affording a S = 13/2 ground state. All of the three compounds exhibit frequency-dependent out-of-phase ac susceptibility signals indicative of slow magnetization relaxation and potential SMM behavior. Among them, 1 and 3 display the out-of-phase χ"(m) peak maximum above 2.0 K. Fitting of the ac susceptibility data to the Arrhenius law gives an energy barrier U(eff) = 9.27/13.83 K for 1 and 3, respectively.

Hepta-carbonyl-bis-(µ-propane-1,3-di-thiol-ato)triiron(I,II)(2 Fe-Fe).

The trinuclear title compound, [Fe3(C3H6S2)2(CO)7], is a mixed-valent Fe(I)/Fe(II) complex and crystallizes with two mol-ecules of similar configuration in the asymmetric unit. The three Fe atoms in each mol-ecule display a bent arrangement [Fe-Fe-Fe = 156.22 (4) and 157.06 (3)°]. Both outer Fe(I) atoms are six-coordinated in a distorted ocahedral coordination geometry defined by the bridging Fe(II) atom, three carbonyl C atoms and two bridging S atoms. The coordination number of the central Fe(II) atom is seven and includes bonding to the two outer Fe(I) atoms, four bridging S atoms and one carbonyl C atom. The resulting coordination polyhedron might be described as a highly distorted monocapped trigonal prism. In the crystal packing, the mol-ecules exhibit a chain-like arrangement parallel to [100] and [001], and the resulting layers are stacked along [010]. The cohesion of the structure is dominated by van der Waals inter-actions.

Efficient photo-driven hydrogen evolution by binuclear nickel catalysts of different coordination in noble-metal-free systems.

Exploration of the complex Ni2(MBD)4 (MBD = 2-mercaptobenzimidazole) (C1) having different coordinated Ni atoms as a photocatalyst for hydrogen evolution is made. For comparison, the bimetallic Ni2(MBT)4 (MBT = 2-mercaptobenthiazole) (C2) complex with the same coordinated Ni atoms was synthesized. Both of the complexes have been successfully constructed for photo-induced hydrogen production using organic dyes as photosensitizers and triethanolamine (TEOA) as the effective electron donor by visible light (>400 nm) in acetonitrile-water solution. The time-dependence of H2 generation and DFT computational studies demonstrate that the complex C1 is more active than C2 for H2 evolution. The mechanisms of photocatalytic hydrogen generation for C1 and C2 involve different protonation sites resulting from the differences between the two structures.

Octanuclear Mn(III)6Mn(II)Ln (Ln = Gd, Dy and Er) clusters with a novel core topology: syntheses, structures, and magnetic properties.

Reactions of [Mn6O2(piv)10(py)2.5(piv)1.5], Ln(NO3)3·6H2O and N-mdeaH2 in MeCN in the presence of Me3SiCl generated a family of octanuclear Mn/Ln complexes [Mn6(III)Mn(II)Ln(N-mdea)3(N-mdeaH)(piv)8O2(OH)3(NO3)(H2O)]·xCH3CN·xH2O [Ln = Gd (1), Dy (2), Er (3), pivH = pivalic acid, N-mdeaH2 = N-methyl diethanolamine]. Each complex possesses a [Mn6(III)Mn(II)Ln(µ3-O)2(µ3-OH)3](16+) core containing two butterfly-like subunits of [Mn3Ln(µ3-OH)2] and [Mn4(µ3-O)2] sharing a common vertex, and an outer Mn atom ligated to one of the subunits through a µ3-OH(-) ligand. The core topology represents a new Mn/Ln core type. The magnetic susceptibility study of 1-3 indicates the presence of dominant antiferromagnetic interactions within the complexes. For complex 1, which contains an isotropic Gd(III) atom, fitting of the obtained M/(NµB) vs. H/T data gave S = 4, g = 1.90, and D = -0.31 cm(-1). The results were further supported by ac data. Complex exhibits out-of-phase ac susceptibility signals, indicating it may be a SMM.

The first heterometallic examples of 3d-4f heptanuclear [Mn(II)3Ln(III)4] complexes with planar disc-like cores and diverse magnetic properties.

A family of heptanuclear [Mn(II)(3)Ln(III)(4)] clusters with planar disc-like cores have been synthesized by a solvothermal route, where Ln = La, Pr, Nd, and Gd, and such fascinating topology is unprecedented in 3d-4f complexes. Dc magnetic susceptibility data show different magnetic behaviors derived from the difference in Ln ions.

Syntheses, structures and magnetic properties of a family of heterometallic [Mn(II)2Mn(III)2Ln(III)2] clusters.

A new family of isostructural Mn-Ln heterometallic clusters, [Mn(II)(2)Mn(III)(2)Ln(III)(2)(Piv)(8)(thme)(2)(H(2)tea)(2)] (H(3)thme = 1,1,1-tris(hydroxymethyl)ethane, Hpiv = pivalic acid, H(3)tea = triethanolamine, and Ln = Pr, Nd, Sm, Eu, Gd, Tb, and Dy) have been prepared by reaction of the hexanuclear manganese precursor, [Mn(6)O(2)(Piv)(10)(4-Me-Py)(2.5)(Hpiv)(1.5)], with H(3)thme, H(3)tea, and Ln(NO(3))(3)·6H(2)O under the solvothermal conditions. Complexes 1Pr-7Dy were characterized by single-crystal X-ray diffraction and their core [Mn(2)(III)Mn(2)(II)Ln(2)(III)(µ(3)-OR)(4)(µ(2)-OR)(6)](6+) composed of four face-sharing defected cubane units. Antiferromagnetic (AF) exchange interactions were suggested for all of the complexes by solid-state dc magnetic susceptibility measurements. Complexes 6Tb and 7Dy, show frequency-dependent ac susceptibility signals suggestive of slow magnetic relaxation.

Efficient [FeFe] hydrogenase mimic dyads covalently linking to iridium photosensitizer for photocatalytic hydrogen evolution.

Two [FeFe] hydrogenase mimics, [Fe(2)(µ-pdt)(CO)(5)L1] (L1 = PPh(2)SPhNH(2)) (Ph = phenyl) (2) and [Fe(2)(µ-pdt)(CO)(5)L2] (L2 = PPh(2)PhNH(2)) (3), and two molecular photocatalysts, [(CO)(5)(µ-pdt)Fe(2)PPh(2)SPhNHCO(bpy)(ppy)(2)Ir]PF(6) (bpy = bipyridine, ppy = 2-phenylpyridine) (2a) and [(CO)(5)(µ-pdt)Fe(2)PPh(2)PhNHCO(bpy)(ppy)(2)Ir](PF(6)) (3a), have been designed and synthesized, anchoring Ir(ppy)(2)(mbpy)PF(6) (mbpy = 4-methyl-4'-carbonyl-2,2'-bipyridine) (PS) to one of the iron centers of complexes 2 and 3 by forming amide bonds. Molecular dyads 2a, 3a and the intermolecular systems 2, 3 with PS have also been successfully constructed for photoinduced H(2) production using triethylamine (TEA) as a sacrificial electron donor by visible light (>400 nm) in CH(3)CN-H(2)O solution. The time-dependence of H(2) generation and spectroscopic studies suggest that the activity of H(2) evolution can be tuned by addition of a S atom to the phosphane ligand. The highest turnover numbers (TON) of hydrogen evolution obtained are 127, using 2a as a photocatalyst in a supramolecular system, and 138, based on catalyst 2 in a multi-component system. Density functional theory (DFT) computational studies demonstrate that the S atom in the second coordination sphere makes complex 2 accept an electron more easily than 3 and improves the activity in light-induced hydrogen production.

Photoswitchable electrochemical behaviour of a [FeFe] hydrogenase model with a dithienylethene derivative.

A diiron dithiolate complex 1o with a dithienylethene (DTE) phosphine ligand has been elaborately designed and fully investigated by spectroscopic and DFT computational studies. Upon irradiation with UV light, the DTE moiety in complex 1o undergoes an excellent photocyclization reaction to attain ring-closed state 1c in high yield (>95%), accompanied by a colour change from orange to deep blue. On the other hand, upon irradiation with visible light (>460 nm), ring-closed form 1c in CH(3)CN solution reverts perfectly into ring-open form 1o. Both 1o and 1c were characterised by IR, (1)H, (31)P, (19)F NMR and electrochemical spectroscopy. The electrochemical behaviours of both the open and closed forms were investigated by cyclic voltammetry. Upon photocyclization reaction, a 290 mV (from -2.29 V to -2.00 V) positive shift is induced in the potential of electrochemical catalytic proton reduction, due to the electron-withdrawing effect of the ring-closed DTE moiety. Consequently, complex 1 can reversibly photoswitch the potential of proton reduction on the [FeFe] moiety.

Syntheses, structures, and magnetic properties of a family of tetra-, hexa-, and nonanuclear Mn/Ni heterometallic clusters.

A family of Mn(III)/Ni(II) heterometallic clusters, [Mn(III)(4)Ni(II)(5)(OH)(4)(hmcH)(4)(pao)(8)Cl(2)]·5DMF (1·5DMF), [Mn(III)(3)Ni(II)(6)(N(3))(2)(pao)(10)(hmcH)(2)(OH)(4)]Br·2MeOH·9H(2)O (2·2MeOH·9H(2)O), [Mn(III)Ni(II)(5)(N(3))(4)(pao)(6)(paoH)(2)(OH)(2)](ClO(4))·MeOH·3H(2)O (3·MeOH·3H(2)O), and [Mn(III)(2)Ni(II)(2)(hmcH)(2)(pao)(4)(OMe)(2)(MeOH)(2)]·2H(2)O·6MeOH (4·2H(2)O·6MeOH) [paoH = pyridine-2-aldoxime, hmcH(3) = 2, 6-Bis(hydroxymethyl)-p-cresol], has been prepared by reactions of Mn(II) salts with [Ni(paoH)(2)Cl(2)], hmcH(3), and NEt(3) in the presence or absence of NaN(3) and characterized. Complex 1 has a Mn(III)(4)Ni(II)(5) topology which can be described as two corner-sharing [Mn(2)Ni(2)O(2)] butterfly units bridged to an outer Mn atom and a Ni atom through alkoxide groups. Complex 2 has a Mn(III)(3)Ni(II)(6) topology that is similar to that of 1 but with two corner-sharing [Mn(2)Ni(2)O(2)] units of 1 replaced with [Mn(3)NiO(2)] and [MnNi(3)O(2)] units as well as the outer Mn atom of 1 substituted by a Ni atom. 1 and 2 represent the largest 3d heterometal/oxime clusters and the biggest Mn(III)Ni(II) clusters discovered to date. Complex 3 possesses a [MnNi(5)(µ-N(3))(2)(µ-OH)(2)](9+) core, whose topology is observed for the first time in a discrete molecule. Careful examination of the structures of 1-3 indicates that the Mn/Ni ratios of the complexes are likely associated with the presence of the different coligands hmcH(2-) and/or N(3)(-). Complex 4 has a Mn(III)(2)Ni(II)(2) defective double-cubane topology. Variable-temperature, solid-state dc and ac magnetization studies were carried out on complexes 1-4. Fitting of the obtained M/(Nµ(B)) vs H/T data gave S = 5, g = 1.94, and D = -0.38 cm(-1) for 1 and S = 3, g = 2.05, and D = -0.86 cm(-1) for 3. The ground state for 2 was determined from ac data, which indicated an S = 5 ground state. For 4, the pairwise exchange interactions were determined by fitting the susceptibility data vs T based on a 3-J model. Complex 1 exhibits out-of-phase ac susceptibility signals, indicating it may be a SMM.

Luminescent square-planar platinum(II) complexes with tridentate 3-bis(2-pyridylimino)isoindoline and monodentate N-heterocyclic ligands.

A series of platinum(II) complexes with 1,3-bis(2-pyridylimino)isoindoline (BPI) derivatives were prepared by substitution of the coordinated Cl in the precursor complex Pt(BPI)Cl with a N-heterocyclic ligand such as pyridine, phthalazine or phenanthridine. These complexes display orange to red luminescence in fluid dichloromethane solutions and in the solid states at room temperature. The photophysical properties were tuned by introducing electron-withdrawing -NO(2) or electron-donating -NH(2) to the BPI ligand. The DFT computational studies suggest that the emission in the N-heterocyclic ligand substituted platinum(II) complexes originates mainly from the (3)[π→π*(BPI)] (3)IL triplet excited state, mixed with some (3)[dπ(Pt)→π*(BPI)] (3)MLCT character. Compared with the precursor Pt(BPI)Cl, both the low-energy absorption and the emission in the N-heterocyclic ligand substituted platinum(II) complexes exhibits a distinct blue-shift due to an obviously enhanced contribution from the (3)IL state and a reduced (3)MLCT character.

Structural interconversion between a chain polymer and a two-dimensional network accompanied by tunable magnetic properties.

The reaction of 2-hydroxypyrimidine-4,6-dicarboxylic acid (H(3)hpdc) with CuCl(2) under different temperatures gives a chain-like compound [Cu(2)(hpdc)(OH)(H(2)O)(4)]·H(2)O and a layer-like compound [Cu(2)(hpdc)(OH)(H(2)O)], which exhibit structural interconversion and tunable magnetic properties upon dehydration and hydration.

(6-Oxido-2-oxo-1,2-dihydropyrimidine-5-carboxylato-κ2O5,O6)bis[2-(2-pyridyl)-1H-benzimidazole-κ2N2,N3]manganese(II) monohydrate.

In the title compound, [Mn(C(5)H(2)N(2)O(4))(C(12)H(9)N(3))(2)]·H(2)O, the Mn(II) centre is surrounded by three bidentate chelating ligands, namely, one 6-oxido-2-oxo-1,2-dihydropyrimidine-5-carboxylate (or uracil-5-carboxylate, Huca(2-)) ligand [Mn-O = 2.136 (2) and 2.156 (3) Å] and two 2-(2-pyridyl)-1H-benzimidazole (Hpybim) ligands [Mn-N = 2.213 (3)-2.331 (3) Å], and it displays a severely distorted octahedral geometry, with cis angles ranging from 73.05 (10) to 105.77 (10)°. Intermolecular N-H···O hydrogen bonds both between the Hpybim and the Huca(2-) ligands and between the Huca(2-) ligands link the molecules into infinite chains. The lattice water molecule acts as a hydrogen-bond donor to form double O···H-O-H···O hydrogen bonds with the Huca(2-) O atoms, crosslinking the chains to afford an infinite two-dimensional sheet; a third hydrogen bond (N-H···O) formed by the water molecule as a hydrogen-bond acceptor and a Hpybim N atom further links these sheets to yield a three-dimensional supramolecular framework. Possible partial π-π stacking interactions involving the Hpybim rings are also observed in the crystal structure.

[1,2-Bis(diphenyl-phosphan-yl)ethane-2κP,P']tetra-carbonyl-1κC,2κC-(µ-2-cyclo-pentyl-2-aza-propane-1,3-dithiol-ato-1:2κS,S':S,S')diiron(II)(Fe-Fe).

In the title compound, [Fe(2)(C(7)H(13)NS(2))(C(26)H(24)P(2))(CO)(4)], the Fe(2)S(2) core exhibits a butterfly-like shape, with two S atoms bridging the Fe-Fe dumbbell. Each of the two Fe atoms exhibits a distorted octa-hedral environment. One Fe atom is additionally bonded to three carbonyl C atoms, whereas the other Fe atom is additionally bonded to one carbonyl C atom and two P atoms of the chelating dppe [dppe = 1,2-bis-(diphenyl-phosphan-yl)ethane] ligand. Non-classical intra-molecular C-H⋯S hydrogen-bonding inter-actions are present in the structure. The packing of adjacent mol-ecules along [100] is accomplished mainly through van der Waals forces.

Synthesis, structures and electrochemistry studies of 2Fe2S-Fe(ii)(S-2N)(2) models for H-cluster of [FeFe]-hydrogenase.

A series of model complexes [(µ-pdt)Fe(2)(CO)(5)](2)M(sip)(2) (M = Fe, Ni) were synthesized as H-cluster analogues of [FeFe]-hydrogenase. Their electrochemical behaviours were investigated and it is proposed that the bridging metal bis(tris-chelate) groups act as electron transfer sites in theses mimics.

The use of phosphonates for constructing 3d-4f clusters at high oxidation states: synthesis and characterization of two unusual heterometallic CeMn complexes.

The use of phosphonic acids in the synthesis of mixed-metal CeMn complexes has led to the formation of two phosphonate complexes with unusual topologies: [Ce(2)Mn(6)O(6)(OH)(5)(t-BuPO(3))(6)(O(2)CMe)(3)] x 53 H(2)O (1 x 53 H(2)O) and [Ce(22)Mn(12)O(34)(MePO(3))(12)(O(2)CMe)(33)(OMe)(6)(NO(3))(H(2)O)(12)](n) (2). The two mixed-metal CeMn complexes were both prepared from a reaction system containing Mn(O(2)CMe)(2) and (NH(4))(2)[Ce(NO(3))(6)] with similar procedures except for using different phosphonic acids (tert-butylphosphonic acid and methylphosphonic acid, respectively) as coligands. Both complexes possess rare topology of triangular type, with compound 1 being a 0D discrete cluster, whereas, compound 2 is a 1D polymer. The octanuclear core of complex 1 is composed of three symmetry equivalent distorted cubanes {Ce(IV)(2)Mn(IV)(2)O(2)(OH)(2)} sharing a trigonal-bipyramidal unit {Ce(IV)(2)(OH)(3)} in the centre. Compound 2 is a one-dimensional chain polymer of identical Ce(22)Mn(12)O(34) units linked together by NO(3)(-) and MeCO(2)(-) groups, while the Ce(22)Mn(12)O(34) unit is constituted by two centrosymmetric Ce(9)(IV)Ce(2)(III)Mn(IV)(6)O(17) subunits, which features three identical distorted cubanes {Ce(IV)(2)Mn(IV)(2)O(4)} connecting to a central trigonal-bipyramidal unit {Ce(IV)(3)O(2)}, and two additional Ce(III) ions capping the top and bottom of the central trigonal bipyramid by six MePO(3)(2-) ligands. Complexes 1 and 2 are the first high-nuclearity Mn/Ln aggregates reported to date using phosphonates as ligands. Magnetic susceptibility measurements reveal that compound 1 displays dominant ferromagnetic interactions between the adjacent metal ions with the best fit parameters for the exchanges are J(1) = 6.186 cm(-1), J(2) = 4.172 cm(-1), and with a result of S = 9 ground state confirmed by the M versus HT(-1) data, which indicates the spins of all the six Mn(IV) ions in the cluster are parallel to each other. In contrast, the data for 2 reveals overall antiferromagnetic couplings within the cluster and a resulting S = 6 ground state. Both the in-phase signal chi'(M)T and out-of-phase signal chi''(M) of the two complexes exhibit frequency-dependent below approximate 3 K.