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.

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.

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.

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.

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.

(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.

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.

Spectroscopic and luminescence studies on square-planar platinum(II) complexes with anionic tridentate 3-bis(2-pyridylimino)isoindoline derivatives.

Reactions of 1,3-bis(2-pyridylimino)isoindoline (HL1), 1,3-bis(2-pyridylimino)benz(f)isoindoline (HL2), or 5,6-dihydro-2,3-diphenyl-5-(pyridin-2-ylimino)pyrrolo[3,4-b]pyrazin-7-ylidene)pyridin-2-amine (HL3) with Pt(tht)(2)Cl(2) (tht = tetrahydrothiophene) afforded the corresponding Pt(L)Cl complexes. A series of neutral platinum(II) alkynyl complexes Pt(L)(C[triple bond]CR) were prepared by reactions of the precursors Pt(L)Cl with alkynyl ligands through CuI-catalyzed platinum acetylide sigma coordination. Crystal structural determination of Pt(L3)Cl (3), Pt(L1)(C[triple bond]CPh) (4), and Pt(L1)(C[triple bond]CC(6)H(4)Bu(t)-4) (6) by X-ray crystallography revealed that the neutral platinum(Pi) complexes with monoanionic tridentate L ligands display more perfect square-planar geometry than that in platinum(II) complexes with neutral tridentate 2,2':6',2''-terpyridyl ligands. Both the Pt(L)Cl and Pt(L)(C[triple bond]CC(6)H(4)R-4) complexes exhibit low-energy absorption at 400-550 nm, arising primarily from pi --> pi*(L) intraligand (IL) and 5d(Pt) --> pi*(L) metal-to-ligand charge-transfer (MLCT) transitions as suggested from density functional theory calculations. They display bright-orange to red room-temperature luminescence in fluid dichloromethane solutions with microsecond to submicrosecond ranges of emissive lifetimes and 0.03-3.79% quantum yields, originating mainly from (3)IL and (3)MLCT excited states. Compared with the emissive state in Pt(L)Cl complexes, substitution of the coordinated Cl with C[triple bond]CC(6)H(4)R-4 in Pt(L)(C[triple bond]CC(6)H(4)R-4) complexes induces an obviously enhanced contribution from the (3)[pi(C[triple bond]CC(6)H(4)R-4) --> pi*(L)] ligand-to-ligand charge-transfer (LLCT) triplet state. The photophysical properties can be finely tuned by modifying both the L and alkynyl ligands. The calculated absorption and emission spectra in dichloromethane coincide well with those measured in a fluid dichloromethane solution at ambient temperature.

Synthesis and characterization of a family of penta- and tetra-manganese(III) complexes derived from an assembly system containing tert-butylphosphonic acid.

A family of manganese complexes, [Mn 5O 3( t-BuPO 3) 2(MeCOO) 5(H 2O)(phen) 2] ( 1), [Mn 5O 3( t-BuPO 3) 2(PhCOO) 5(phen) 2] ( 2), [Mn 4O 2( t-BuPO 3) 2(RCOO) 4(bpy) 2] (R = Me, ( 3); R = Ph, ( 4)), NBu (n) 4[Mn 4O 2(EtCOO) 3(MeCOO) 4(pic) 2] ( 5), NR' 4[Mn 4O 2( i-PrCOO) 7(pic) 2] (R' = Bu (n) , ( 6); R' = Et, ( 7)), were synthesized and characterized. The seven manganese clusters were all prepared from a reaction system containing tert-butylphosphonic acid, Mn(O 2CR) 2 (R = Me, Ph) and NR' 4MnO 4 (R' = Bu (n) , Et) with similar procedures except for using different N-containing ligands (1,10-phenanthroline (phen), 2,2'-bipyridine (bpy) and picolinic acid (picH)) as coligands. The structures of these complexes vary with the N-containing donors. Both the cores of complexes 1 and 2 feature three mu 3-O and two capping t-BuPO 3 (2-) groups bridging five Mn (III) atoms to form a basket-like cage structure. Complexes 3 and 4 both have one [Mn 4(mu 3-O) 2] (8+) core with four coplanar Mn (III) atoms disposed in an extended "butterfly-like" arrangement and two capping mu 3- t-BuPO 3 (2-) binding to three manganese centers above and below the Mn 4 plane. Complexes 5, 6, and 7 all possess one [Mn 4(mu 3-O) 2] (8+) core just as complexes 3 and 4, but they display a folded "butterfly-like" conformation with the four Mn (III) atoms nonplanar. Thus, the seven compounds are classified into three types, and three representative compounds 1.2H 2O.MeOH.MeCN , 3.6H 2O.2MeCOOH , and 5.0.5H 2O have been characterized by IR spectroscopy, ESI-MS spectroscopy, magnetic measurements and in situ UV-vis-NIR spectroelectrochemical analysis. Magnetic susceptibility measurements reveal the existence of both ferromagnetic and antiferromagnetic interactions between the adjacent Mn (III) ions in compound 1.2H 2O.MeOH.MeCN , and antiferromagnetic interactions in 3.6H 2O.2MeCOOH and 5.0.5H 2O. Fitting the experimental data led to the following parameters: J 1 = -2.18 cm (-1), J 2 = 6.93 cm (-1), J 3 = -13.94 cm (-1), J 4 = -9.62 cm (-1), J 5 = -11.17 cm (-1), g = 2.00 ( 1.2H 2O.MeOH.MeCN ), J 1 = -5.41 cm (-1), J 2 = -35.44 cm (-1), g = 2.13, zJ' = -1.55 cm (-1) ( 3.6H 2O.2MeCOOH ) and J 1 = -2.29 cm (-1), J 2 = -35.21 cm (-1), g = 2.02, zJ' = -0.86 cm (-1) ( 5.0.5H 2O ).

Diiron models for the active site of Fe-only hydrogenase with terminal organosulfur ligation: synthesis, structures and electrochemistry.

Diiron model complexes (micro-SCH(2)CH(2)CH(2)S)Fe(2)(CO)(5)L with thioether-substitution, L=S(CH(2)CH(3))(2) (2), S(CH(2)CH(3))(CH(2)CH(2)Cl) (3), S(CH(2)CH(3))(C(6)H(5)) (4), or sulfoxide-substitution, L=SO(CH(2)CH(2)CH(3))(2) (5), SO(CH(3))(2) (6), were synthesized as active site analogues of Fe-only hydrogenase. The organosulfur ligands were introduced into the diiron centers via moderately stable intermediates following two routes. The X-ray crystallographic structures of complexes 2-6 show the apical positions of terminal organosulfur ligands. The electrochemical behaviors of the model complexes were investigated, especially for the interesting properties of the derivative of 6 which is proposed to be the first model with weak donor ligand similar to CO.

[2-(2-Pyridyl)-1H-benzimidazole-kappa2N2,N3]bis(p-toluato-kappa2O,O')manganese(II).

In the title compound, [Mn(C8H7O2)2(C12H9N3)], the manganese(II) centre is surrounded by three bidentate chelating ligands, namely, one 2-(2-pyridyl)benzimidazole ligand [Mn-N = 2.1954 (13) and 2.2595 (14) A] and two p-toluate ligands [Mn-O = 2.1559 (13)-2.2748 (14) A]. It displays a severely distorted octahedral geometry, with cis angles ranging from 58.87 (4) to 106.49 (5) degrees. Intermolecular C-H...O hydrogen bonds between the p-toluate ligands link the molecules into infinite chains, and every two neighbouring chains are further coupled by N-H...O and C-H...O hydrogen bonds between the 2-(2-pyridyl)benzimidazole and p-toluate ligands, leading to an infinite ribbon-like double-chain packing mode. The complete solid-state structure can be described as a three-dimensional supramolecular framework, stabilized by these intermolecular hydrogen-bonding interactions and possible C-H...pi interactions, as well as stacking interactions involving the 2-(2-pyridyl)benzimidazole ligands.

Bis(acetyl-acetonato)oxido(triphenyl-phosphine oxide)vanadium(IV).

In the structure of the title compound, [V(C(5)H(7)O(2))(2)O(C(18)H(15)OP)], the V atom adopts a slightly distorted octa-hedral geometry with its coordination completed by four O atoms of two acetyl-acetonate (acac) ligands, one oxo group and one O atom of the triphenyl-phosphine oxide (OPPh(3)) ligand.

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.

Studies on the Synthetic System of V/Ag/S Cluster Compounds and Structural Characterizations of V(2)AgS(4), V(2)Ag(2)S(4), and V(2)O(2)(&mgr;-S)(2) Complexes.

The reaction system (NH(4))(3)VS(4)/Ag(PPh(3))(2)Cl/R(2)dtcNa in CH(3)CN was studied to afford two V(2)Ag(1)(-)(2)S(4) cubanelike cluster compounds and a trinuclear V(3)O(3)S(2) complex. (Et(4)N)[V(2)AgS(4)(Me(2)dtc)(2)(PPh(3))].(1)/(2)CH(3)CN ([Et(4)N]1.(1)/(2)CH(3)CN) crystallizes in the monoclinic space group P2(1)/c with a = 10.525(3) Å, b = 16.340(8) Å, c = 26.834(8) Å, beta = 101.28(2) degrees, and Z = 4. Complex (Et(4)N)(2)[V(2)Ag(2)S(4)(CS(3))(2)(PPh(3))(2)] ([Et(4)N](2)2) crystallizes in the monoclinic space group C2/c with a = 21.212(5) Å, b = 20.100(4) Å, c = 15.039(2) Å, beta = 102.72(2) degrees, and Z = 4. A stepwise aggregate process including a dinuclear V(2)Y(2)(&mgr;-S)(2) (Y = S, O) intermediate was suggested to explain the formation of 1, 2, and trinuclear anion [V(3)O(&mgr;-O)(2)(&mgr;-S)(2)(Et(2)dtc)(3)](-). Structural features of these complexes show that the V(2)Y(2)(&mgr;-S)(2) moiety can be seen as an independent unit to combine with other metal ion(s). A complex containing the [V(2)O(2)(&mgr;-S)(2)(Et(2)dtc)(2)](2)(-) (3) cluster anion was separated from a reaction system of (NH(4))(3)VS(4)/PPh(3)/Et(2)dtcNa, and its solvate complex {(Et(4)N)(3)Na[V(2)O(2)(&mgr;-S)(2)(Et(2)dtc)(2)](2)}(2).(1)/(2)CH(3)OH.H(2)O crystallizes in orthorhombic space group Pnn2 with a = 31.599(1) Å, b = 17.228(5) Å, c = 14.104(7) Å, and Z = 2. Infrared frequencies at 844-970 cm(-1) were associated with a V=O stretching vibration. The V=O additional coordination to the other metal ion gives rise to the red shift of the frequency. Proton and (51)V NMR spectra exhibit a paramagnetic V(IV) center existing in the trinuclear complex (Et(4)N)[V(3)O(&mgr;-O)(2)(&mgr;-S)(2)(Et(2)dtc)(3)] ([Et(4)N]4) and d(1)-d(1) coupling of V-V of the V(2)Y(2)(&mgr;-S)(2) moiety for these complexes. Two sets of the (31)P signals for 2at 16.6-19.3 ppm with equal intensity are attributed to (31)P-(107)Ag coupling and may well hide two V atoms in a similar environment. Cyclic voltammetries show some similar electrochemical behaviors between 3 and 4 indicated by a common couple at -0.7 V/-0.65 V and an oxidation peak at +0.7 to +0.6 V which are proposed to be due to redox in the V(2)O(2)(&mgr;-S)(2) moiety.

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.

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.

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.

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 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.