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Eight [CNN] pincer nickel NHC chlorides, [RCcarbeneNamidoR′2Namine–Ni–Cl] (R/R′2 = quinolinyl/nBu (3a), quinolinyl/Me (3b), quinolinyl/PhCH2 (3c), (CH2)4/nBu (5a), (CH2)4/iPr (5b), Me2/nBu (5c), Me2/iPr (5d), and Me2/PhCH2 (5e)), were prepared by the reactions of related asymmetric [CNN] NHC preligands with Ni(DME)Cl2via N–H bond activation. The molecular structures of complexes 3a, 3b and 5a were investigated using single crystal XRD. The catalytic experiments showed that the nickel complexes could catalyze the hydrosilylation of unsaturated compounds like aldehydes and ketones, and complex 3b was found to exhibit the best catalytic activity at 30 °C. Using NaBHEt3 as an additive, the catalytic activity of 3b was greatly improved. Furthermore, it was found that good to complete conversion of aldehydes could be achieved within 1.5 h at 30 °C after pre-reacting 3b and NaBHEt3 with silane for 0.5 h. The substrate ketones could be converted to alcohols in good yields by prolonging the reaction time to 2.5 h at 30 °C. It is worth mentioning that all eight [CNN] pincer nickel NHC chlorides are stable in air, and this is rare in nickel catalysts for hydrosilylation of aldehydes and ketones. Moreover, the substrate universality of the catalytic system is also very good, with good functional group tolerance. The molecular structures of complexes 3a, 3b and 5a were investigated using single crystal XRD and a possible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

Three novel iron dinitrogen hydrides, [FeH(iPr-PSiMeP)(N2)(PMe3)] (1), [FeH(iPr-PSiPhP)(N2)(PMe3)] (2), and [FeH(iPr-PSiPh)(N2)(PMe3)] (3), supported by a silyl ligand are synthesized for the first time by changing the electronic effect and steric hindrance of the ligands through the reaction of ligands L1–L3 with Fe(PMe3)4 in a nitrogen atmosphere. The ligands containing an electron-donating group with large steric hindrance on the phosphorus atom are beneficial for the formation of dinitrogen complexes. A penta-coordinate iron hydride [FeH(iPr-PSiPh)(PMe3)2] (4) was formed through the reaction of ligand L3 with Fe(PMe3)4 in an argon atmosphere under the same conditions. The reactions between complexes 1–3 with an atmospheric pressure of dihydrogen gas resulted in Fe(II) dihydrides, [(iPr-PSiMe(μ-H)P)Fe(H)2(PMe3)] (5), [(iPr-PSiPh(μ-H)P)Fe(H)2(PMe3)] (6) and [(iPr-PSiPh(μ-H))Fe(H)2(PMe3)2] (7), with an η2-(Si–H) coordination. The isolation of dihydrides 5–7 demonstrates the ability of the dinitrogen complexes 1–3 to realize the activation of dihydrogen under ambient temperature and pressure. The molecular structures of complexes 1–7 were elucidated by single crystal X-ray diffraction analysis. The iron dinitrogen hydrides 1–3 are effective catalysts for the silylation of dinitrogen under ambient conditions and among them 3 is the best catalyst. [ABSTRACT FROM AUTHOR]

In this study, two [PCP] pincer silylene cobalt(I) complexes [((Ph2POCH2)2CH)Co(PMe3)(SiCl((NtBu)2CAr))] (Ar = Ph (2) and 4-MePh (3)) were synthesized through the substitution reaction of the [PCP] pincer cobalt(I) complex [((Ph2POCH2)2CH)Co(PMe3)2] (1) with silylene ligands: SiCl((NtBu)2CAr) (Ar = Ph (L1) and 4-MePh (L2)). The reaction of complex 2 with CO afforded the carbonyl silylene cobalt(I) complex [((Ph2POCH2)2CH)Co(CO)(SiCl((NtBu)2CPh))] (4), while complex 2 reacted with CH3I to give rise to cobalt(II) iodide [((Ph2POCH2)2CH)Co(I)(PMe3)] (6). With a catalyst loading of 2 mol%, complex 6 displayed efficient catalytic activity for hydrosilylation of alkenes by using Ph2SiH2 as the hydrogen source under mild conditions. The molecular structures of complexes 2, 3, 4 and 6 were determined by single crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

A novel mononuclear palladium(II) complex, [Pd(L)Cl2]·DMF (1·DMF, L = 1,4-bis(5-amino-1,3,4-thiadiazol-2-sulfanyl-methyl)benzene), has been synthesized and characterized by elemental analysis, FT-IR and 1H NMR spectroscopy and single-crystal X-ray diffraction. On the basis of the molecular structure, in 1·DMF, a ligand acts as a bidentate chelating one using its endocyclic nitrogen atoms. The biological activities of the free ligand and its palladium complex including cytotoxic activity towards the human colon cancer cell line (HCT-116) and antibacterial activity against one Gram-negative strain (Escherichia coli (ATCC 25922)) and one Gram-positive strain (Staphylococcus aureus (ATCC 6538)) have been examined. The IC50 value of 1·DMF against HCT-116 was 500 μM, which is much higher than that reported for cisplatin, and hence, the compound exhibited low anticancer efficacy compared to cisplatin. However, it exhibited excellent antibacterial activities against both Gram-negative as well as Gram-positive bacterial microorganisms. Furthermore, the thermal stability of complex 1·DMF was studied by thermal gravimetric analysis (TGA). The resulting product was characterized as highly pure PdO nanoparticles (mean crystallite size: 39 nm) by using a series of techniques including powder XRD, EDAX, and SEM. [ABSTRACT FROM AUTHOR]

Five [PSiP]-pincer iron hydrides 1–5, [(2-Ph2PC6H4)2HSiFe(H)(PMe3)2 (1), (2-Ph2PC6H4)2MeSiFe(H)(PMe3)2 (2), (2-Ph2PC6H4)2PhSiFe(H)(PMe3)2 (3), (2-(iPr)2PC6H4)2HSiFe(H)(PMe3) (4), and (2-(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (5)], were used as catalysts to study the effects of pyridine N-oxide and the electronic properties of [PSiP]-ligands on the catalytic hydrosilylation of carbonyl compounds. It was proved for the first time that this catalytic process could be promoted with pyridine N-oxide as the initiator at 30 °C because the addition of pyridine N-oxide is beneficial for the formation of an unsaturated hydrido iron complex, which is the key intermediate in the catalytic mechanism. Complex 4 as the best catalyst shows excellent catalytic performance. Among the five complexes, complex 3 was new and the molecular structure of complex 3 was determined by single crystal X-ray diffraction. A proposed mechanism was discussed. [ABSTRACT FROM AUTHOR]

The dehydration of primary amides to their corresponding nitriles using four [PSiP]‐pincer hydrido iron complexes 1–4 [(2‐Ph2PC6H4)2MeSiFe(H)(PMe3)2 (1), (2‐Ph2PC6H4)2HSiFe(H)(PMe3)2 (2), (2‐(iPr)2PC6H4)2HSiFe(H)(PMe3)2 (3) and (2‐(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (4)] as catalysts in the presence of (EtO)3SiH as dehydrating reagent was explored in the good to excellent yields. It was proved for the first time that Lewis acid could significantly promote this catalytic system under milder reaction conditions than other Lewis acid‐promoted system, such as shorter reaction time or lower reaction temperature. This is also the first example that dehydration of primary amides to nitriles was catalyzed by silyl hydrido iron complexes bearing [PSiP]‐pincer ligands with Lewis acid as additive. This catalytic system has good tolerance for many substituents. Among the four iron hydrides 1 is the best catalyst. The effects of substituents of the [PSiP]‐pincer ligands on the catalytic activity of the iron hydrides were discussed. A catalytic reaction mechanism was proposed. Complex 4 is a new iron complex and was fully characterized. The molecular structure of 4 was determined by single crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

The reaction of copper(4-(tert-butyl)phenyl)methanethiolate [CuSCH2C6H4tBu] with bis(trimethylsilyl)sulfide S(SiMe3)2 in the presence of triphenylphosphine PPh3 afforded the binary 52 nuclear copper cluster [Cu52S12(SCH2C6H4tBu)28(PPh3)8]. The molecular structure of this intensely red coloured nanoscale Cu2S mimic was established by single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Fully structural interconversions between monomeric Pd2L4 and interlocked dimeric Pd4L8 cages have been investigated to elucidate their thermodynamic stability defined by their anion-guest binding behaviours. [ABSTRACT FROM AUTHOR]

The synthesis, molecular structures and luminescence properties of two 'Cu12S6' cluster molecules with stabilizing bidentate phosphine ligands are described. Both display in the solid state at ambient temperature high photoluminescence quantum yields (≥48%) and good stability towards oxygen. [ABSTRACT FROM AUTHOR]

Ag6L6-type coordination nanotubular structures have been assembled from 6 Ag(i) ions and 6 T-shaped ligands, 4-(3,5-bis(diphenylphosphino)phenyl)pyridine; the nanotubes represent a discrete molecular architecture of a number of polymeric structures assembled from dimeric building blocks. [ABSTRACT FROM AUTHOR]

Studies the crystal structure of acetonitrile[2,6-bis(pyrazol-1-y)pyridine](isonicotinamide) copper(II) cation. Conformation of the pyridine ring of the isonicotinamide ligand; Structural parameters of the hydrogen-bonded contacts.

CuCI and bis(diphenylphosphanyl)metharre (dppm) react in the presence of small amounts of FeCl3 with PhSeSiMe3 and Se(SiMe3)2 to yield [Cu30Fe2Se6(SePh)24(dppm)4]. The crystal structure of the compound was determined by single-crystal X-ray analysis to give a mixed copper selenide/selenolate cluster molecule of a new structural type incorporating Iwo central iron atoms. The formal oxidation state of the iron atoms was determined by Mbssbauer spectroscopy to be +3, in agreement with quantum chemical calculations and modeling of the magnetic data. In addition, Mdssbauer studies show no magnetic hyperfine structure in zero field, and the magnetically perturbed spectrum displays a pattern typical tora diamagnetic species in a transverse field, suggesting a singlet ground state. However, the inclusion of the iron atoms has a distinct influence on the optical properties of the compound compared to similar clusters containing only copper and selenium atoms. [ABSTRACT FROM AUTHOR]

• Synthesis and characterization of two novel Pd(II)-Na Schiff base complexes. • Evaluation of cytotoxicity of both complexes towards MCF-7 human breast cancer. • Assessment of in vitro antibacterial activity of both synthesized compounds. • Characterization of nanoscaled products of both complexes upon pyrolysis. Novel bi- and trinuclear palladium(II)-sodium complexes, {[P d L]Na(NO 3)(EtOH)} (1) and {[P d L] 2 Na}Cl (2) based on salophen-type Schiff base N,N'-(1,2-phenylene)-bis(3-methoxysalicylideneimine) (H 2 L) were synthesized under ambient and sonochemical conditions. Ultrasonication proved to be a more effective method for the rapid synthesis of these bi- and trinuclear complexes under mild conditions. On the basis of the molecular structure of complexes 1 and 2 , each palladium atom is placed in the "inner" N 2 O 2 compartment, and the sodium atoms are located in the "outer" O 2 O' 2 compartment of the twofold deprotonated bis -Schiff base ligand. In both complexes, each Pd(II) ion is four coordinated showing square planar geometry, whereas the Na(I) ions in complexes 1 and 2 adopt two different geometries, namely hepta and octa coordination, respectively. In addition, the solventless thermolysis of both complexes at 500 °C was also studied by thermal gravimetric analysis (TGA). EDX and powder XRD data pointed out the presence of highly pure nanoscaled materials. Furthermore, the anticancer and antibacterial activities of bi- and trinuclear complexes were examined towards MCF-7 human breast cancer cell line and evaluated against one gram-negative strain (Escherichia coli ATCC 25922) and one gram-positive strain (Staphylococcus aureus ATCC 6538). The in vitro studies revealed that complex 2 exhibited higher anticancer activity against MCF-7 cell line as well as better antibacterial effect on the examined bacteria strains than complex 1. [Display omitted] [ABSTRACT FROM AUTHOR]

Three diorganocobalt chlorides [CoClMe(PMe3)2-{(C5H6)- CH=O}] (4), [CoClMe(PMe3)2-{(C6H8)-CH=O}] (5), and [CoClMe(PMe3)2-{(C6H7Memeta)-CH=O}] (6) were synthesized through cyclometalation reactions with aldehyde as an anchoring group involving aliphatic vinylic C-Cl bond activation. Complexes 4-6 were characterized by IR and NMR spectroscopy. The crystal and molecular structures of complexes 4 and 5 were determined by single-crystal X-ray diffraction. Complexes 4-6 are stable in solution at room temperature, but they decompose at above 30°C affording C,C-couplings products with the formation of [Co(PMe3)3Cl]. The results of this work will be important for people to deepen the understanding of the C-Cl bond activation mechanism. [ABSTRACT FROM AUTHOR]