Synthesis,characterization, and reactivity of self-assembled tetranuclear arene ruthenium metalla-rectangles

Self-assembly of 4,4′-bipyridine (bpy) with arene-ruthenium building blocks and 2,2′-bisbenzimidazole (H₂BiBzIm) in the presence of AgOTf (OTf = OSO₂CF₃) afforded tetranuclear cations of the type [Ru₄(η⁶-arene)₄(bpy)₂(BiBzIm)₂]⁴⁺ (arene = p-ⁱPrC₆H₄Me 1, C₆Me₆ 2), while similar reactions by use of [(η⁶-C₆Me₆)Ru(μ-Cl)Cl]₂ and excess AgOTf led to isolation of a cationic coordination network {[Ru₄(η⁶-C₆Me₆)₄(bpy)₂(BiBzIm)₂·Ag₂(OTf)₄]²⁺}_n (3), which could also be obtained by treatment of [2][OTf]₄ with AgOTf in methanol. Complex 3 is constructed by π coordination of BiBzIm(η²-carcon) with Ag(I). The coordination geometry around the silver(I) ion is pseudo-tetrahedral (taking the C=C group as one ligand). Self-assembly of only two components: [(η⁶-C₆Me₆)Ru(μ-Cl)Cl]₂ reacted with the 3-pyridyl-bian (mPy-bian) linker in the presence of limited AgOTf to give a chloro-bridged metalla-rectangle [Ru₄(η⁶-C₆Me₆)₄(μ-Cl)₄(mPy-bian)₂Ag]⁵⁺ (4), which enclosed a silver in the center. The coordination geometry around silver(I) in 4 is unusual square planar. The molecular structures of 1–4 were confirmed by X-ray crystallography along with other spectroscopic properties.     

Two cadmium(II) 1-D coordination polymers, {[Cd2(μ-Cl)4Cl2(CH3OH)(H2O)] · (H-aql)2} n and [Cd(μ-Cl)2(aql)] n : synthesis,crystal structures and fluorescent properties

Two Cd(II) 1-D chain coordination polymers with Cd–Cl-Cd–Cl 1-D chains as bases, one connected to protonated 8-aminoquinoline by intermolecular hydrogen bonds {[Cd₂(μ-Cl)₄(Cl)₂(CH₃OH)(H₂O)]·(H-aql)₂} _n (1) (aql = 8-aminoquinoline) and the other to 8-aminoquinoline [Cd(μ-Cl)₂(aql)] _n (2), have been synthesized and structurally characterized by single-crystal X-ray analysis. 1 belongs to the monoclinic system with space group P2(1)/m and 2 belongs to the monoclinic system with space group C2/c. Fluorescent properties of aql, 1, and 2 showed that the fluorescence spectrum (λ_max = 386 nm) of 1 is mainly of aql ππ* character. The fluorescence spectrum of 2 which emits blue-green light (λ_max = 497 nm) mainly involves a metal-perturbed intraligand ππ* transition from strong covalent bonds. Thermal stabilities of 1 and 2 have also been studied.     

Syntheses of (η6-p-cymene)ruthenium(II) piano-stool amine complexes: molecular structure of [(η6-C10H14)RuCl2(H2N-C6H4-p-Cl)]

The dimeric complex [{(η⁶-p-cymene)Ru(μ-Cl)Cl}₂] (1) reacts with S,N-donor Schiff base ligands, para-substituted S-(thiophen-2-ylmethylene)phenylamines in methanol to give mononuclear amine complexes of the type [(η⁶-p-cymene)RuCl₂(NH₂–C₆H₄–p-X)] {X?=?H (2a); X?=?CH₃ (2b); X?=?OCH₃ (2c); X?=?Cl (2d); Br (2e) X?=?NO₂ (2f), respectively} by hydrolysis of the imine group of the ligand after coordination to the metal. The complexes were characterized by analysis and IR and NMR spectroscopy. The molecular structure of [(η⁶-C₁₀H₁₄)RuCl₂(H₂N–C₆H₄–p-Cl)] (2d) was established by a single-crystal X-ray diffraction study.     

Synthesis,characterization, and some electrocatalytic properties of heteromultinuclear FeI/RuII Clusters

A series of new heteromultinuclear Fe^I/Ru^II clusters are described. The complexes (η⁶-arene)RuFe₂S₂(CO)₆ (arene = p-cymene 1 , C₆Me₆ 2 ) and Fe₂[μ-S (Cp*Ru)(CO)₂]₂(CO)₆ (Cp* = η⁵-C₅Me₅) ( 3 ) were prepared by the reduction reactions of (μ-S)₂Fe₂(CO)₆ with 2 equiv of LiHBEt₃, followed by treatment (μ-SLi)₂Fe₂(CO)₆ with ruthenium-arene complexes Ru₂(μ-Cl)₂Cl₂(η⁶-arene)₂ or Cp*Ru (CO)₂Cl in 22–33% yields. Further reactions of 1 and 2 with 1 equiv of triphenylphosphine in the presence of the decarbonylating agent Me₃NO·2H₂O, afforded the corresponding monophosphine-substituted Fe^I/Ru^II complexes (η⁶-arene)RuFe₂S₂(CO)₅(Ph₃P) (arene = p-cymene 4 , C₆Me₆ 5 ) in 75% and 78% yields. While treatment of parent complex 1 or 2 with 1 equiv of diphosphine Ph₂PCH₂PPh₂ (dppm) in xylene at reflux temperature resulted in the formation of the diphosphine-bridged RuFe₂S₂(CO)₉ derivate RuFe₂S₂(CO)₇(dppm) ( 6 ). The possible pathway for the formation was proposed. Two isomers of novel macrocyclic complexes involve the (η⁶-arene) Ru-bridged quadruple-butterfly Fe/S clusters [{μ-S (CH₂)₃S-μ}{(μ-CS₂)Fe₂(CO)₆}₂]₂[(η⁶-arene)Ru]₂ (arene = p-cymene 7a and 7b , C₆Me₆ 8a and 8b ) were isolated by reactions of two μ-CS₂-containing dianion [{μ-S (CH₂)₃S-μ}{(μ-S=CS)Fe₂(CO)₆}₂]²⁻ with [Ru₂(μ-Cl)₂Cl₂(η⁶-arene)₂], in which the propylene groups are attached to two S atoms by ee and ea types of bonds respectively. All the new complexes 1 – 8 have been characterized by elemental analysis, spectroscopy, and particularly for 1 – 6 , 7b and 8a by X-ray crystallography. In addition, the electrochemical properties of representative complexes 1 – 4 and 6 have been investigated.     

Hydroxylation of azomethine carbon: isolation of complexes of η5 and η6-cyclic hydrocarbon platinum group metals with a new Schiff-base ligand

A new Schiff base, (pyridin-2-yl)-N-(3,5-di(pyridin-2-yl)-4H-1,2,4-triazol-4-yl)methanimine, (L), was synthesized. Reaction of [(η⁶-arene)Ru(µ-Cl)Cl]₂ and [Cp*M(µ-Cl)Cl]₂ (M = Rh and Ir) with one equivalent of L in the presence of NH₄PF₆ in methanol yielded dinuclear complexes, [(η⁶-arene)₂Ru₂(L-OH)Cl](PF₆)₂ {arene = C₆H₆ (1), p-ⁱPrC₆H₄Me (p-cymene) (2) and C₆Me₆ (3)}, and [Cp*₂M₂(L-OH)Cl](PF₆)₂ [M = Rh (4) and Ir (5)], respectively, leading to the formation of five new chiral complexes with –OH on the azomethine carbon. L is a pentadentate ligand where one of the metal centers is coordinated to two nitrogen atoms in a bidentate chelating fashion while the other metal is bonded tridentate to three nitrogen atoms. Although the ligand is neutral before coordination, after complexation it is anionic (uni-negative) with negative charge on the azo nitrogen {see the structures: N(5) in 2[PF₆]₂ and N(3) for 4[PF₆]₂}. The complexes have been characterized by various spectroscopic methods including infrared and ¹H NMR and the molecular structures of the representative complexes are established by single-crystal X-ray diffraction studies.     

Synthesis and structural characterization of two cationic dinuclear cymene-ruthenium(II) complexes with thiolato and chloro bridges

Treatment of [(p-cymene)RuCl₂]₂ with HSp-Tol or HSCH₂Ph in the presence of K[PF₆] gave the cationic dinuclear cymene–ruthenium(II) complexes [(p-cymene)₂Ru₂(μ-Cl)(μ-Sp-Tol)₂][PF₆] (1) and [(p-cymene)₂Ru₂(μ-Cl)(μ-SCH₂Ph)₂][PF₆] (2), respectively, which have been characterized by IR, NMR spectroscopies and mass spectrometry along with microanalyses. Their crystal structures were determined by single-crystal X-ray diffraction analyses. The structures of the cationic complexes contain the unusual pseudo-trigonal-bipyramidal Ru₂S₂Cl framework without a ruthenium–ruthenium single bond. The two p-cymene–ruthenium units are held together by two bridging thiolates and one bridging chloride.     

Synthesis,characterization, and polyphenol oxidase activity of CuII,MnII, and FeIII complexes with a N2O2 ligand

To explore the effect of the metal center on catechol oxidase and tyrosinase activities, four complexes, Cu₂(μ-Cl)₂(hbpg)₂ (1), [Cu₂(μ-OH₂)₂(hbpg)₂](NO₃)₂(H₂O)₂ (2), [Fe₂(μ-Cl)₂(hbpg)₂]Cl₂(H₂O)₂ (3), and [Mn₂(μ-Cl)₂(hbpg)₂](H₂O)₂ (4) (hbpg?=?N-(2-hydroxybenzyl)-N-(2-picolyl)glycine), were synthesized and characterized with elemental analysis, single-crystal X-ray diffraction, molar conductivity measurements, mass spectrometry, UV-Visible, and FT-IR spectroscopies. The X-ray crystal structural analysis indicates that 1 has a binuclear copper, coordinated with N₂O₂ ligands. Complementary characterizations suggested that 2, 3, and 4 have similar coordination sphere. Complex 3 exhibits much higher catechol oxidase and tyrosinase-like activity than 1, 2, and 4. The results suggested that with a similar coordination sphere, the redox potential of the metal center is critical for catalytic activity. This work provides valuable information for improving the polyphenol oxidase activity of metal complexes for phenolic degradation.     

Transition Metal Halide Salts and Complexes of 2-Aminopyrimidine: Cobalt(II) and Nickel(II) compounds,Crystal Structures of Bis(2-Aminopyrimidinium)MX4 [M = Co,Ni; X = Cl,Br] and 2-Aminopyrimidinium(+2) [NiBr2(H2O)4]Br2

The reaction of MX₂ (M = Co(II), Ni(II); X = Cl, Br) with 2-aminopyrimidine in aqueous acid yields compounds [(2-apmH)₂MX₄], (2-apmH)₂[MX₄], or (2-apmH₂) [MX₂(H₂O)₄]X₂ (2-apmH = 2-aminopyrimidinium; 2-apmH₂ = 2-aminopyrimidinium(2+)). All compounds have been characterized by single crystal X-ray diffraction. The compounds [(2-apmH)₂MX₄] with M = Co, X = Cl (1); M = Ni, X = Cl (3); and M = Ni, X = Br (4) are isomorphous and crystallize as nearly square planar MX₄ units with the 2-apmH cations coordinated in the axial sites through the unprotonated ring nitrogen. (2-ApmH)₂[CoBr₄] (2) crystallizes as the salt with a nearly tetrahedral CuBr₄ ^2- anion. (2-ApmH₂)[NiBr₂(H₂O)₄]Br₂ (5) forms as a cocrystal of the neutral, six-coordinate nickel complex and (2-ampH₂)Br₂, stabilized by extensive hydrogen bonding. Crystal data (1): monoclinic, P2₁/c, a = 7.540(4), b = 12.954(4), c = 7.277(3) Å, β = 110.09(6), V = 667.4(5) ų, Z = 2, D_calc = 1.955 Mg/m³, μ = 2.079 mm^-1, R = 0.0501 for [|I|≥2(I)]. For (2): triclinic, P-1, a = 7.720(2), b = 7.916(2), c = 14.797(3) Å, α = 97.264(3), β = 104.788(3), γ = 105.171(3)°, V = 825.3(3) ų, Z = 2, D_calc = 2.296 Mg/m³, μ = 10.715 mm^-1, R = 0.0308 for [|I|≥2(I)]. For (3): monoclinic, P2₁/c, a = 7.595(3), b = 12.891(4), c = 7.204(3) Å, β = 111.07(3)°, V = 658.2 ų, Z = 2, D_calc = 1.982 Mg/m³, μ = 2.279 mm^-1, R = 0.0552 for [|I|≥2(I)]. For (4): monoclinic, P2₁/c, a = 7.840(2), b = 13.358(4), c = 7.518(2) Å, β = 110.923(3)°, V = 938.6(3) ų, Z = 2, D_calc = 2.577 Mg/m³, μ = 12.18 mm^-1, R = 0.0280 for [|I|≥2(I)]. For (5): orthorhombic, Pnma, a = 16.776(6), b = 11.943(4), c = 7.079(3) Å, V = 1418.2(9) ų, Z = 4, D_calc = 2.564 Mg/m³, μ = 12.639 mm^-1, R = 0.0381 for [|I|≥2σ(I)].     

Direct Observation by Electrospray Ionization Mass Spectrometry of [Cp*RhMo3O8(OMe)5]−, a Key Intermediate in the Formation of the Double-Bookshelf-Type Oxide Cluster [(Cp*Rh)2Mo6O20(OMe)2]2−

The use of methanol as solvent is essential for the formation of the double-bookshelf-type oxide cluster [(Cp*Rh)₂Mo₆O₂₀(OMe)₂]²⁻ from [{Cp*Rh(μ-Cl)Cl}₂] and four equivalents of [Mo₂O₇]²⁻. The reaction proceeds via [Cp*RhMo₃O₈(OMe)₅]⁻. The proposed structure for this key intermediate (shown schematically) is supported by electrospray ionization mass spectrometry and labeling experiments with CD₃OD as solvent. Cp*=η⁵-C₅Me₅.     

Halogenation of the Hexaphosphabenzene Complex [(Cp*Mo)2(μ,η6:η6-P6)]: Snapshots on the Reaction Progress

The oxidation of [(Cp*Mo)₂(μ,η⁶:η⁶-P₆)] ( 1 ) with halogens or halogen sources was investigated. The iodination afforded the ionic complexes [(Cp*Mo)₂(μ,η³:η³-P₃)(μ,η¹:η¹:η¹:η¹-P₃I₃)][X] (X=I₃⁻, I⁻) ( 2 ) and [(Cp*Mo)₂(μ,η⁴:η⁴-P₄)(μ-PI₂)][I₃] ( 3 ), while the reaction with PBr₅ led to the complexes [(Cp*Mo)₂(μ,η³:η³-P₃)(μ-Br)₂][Cp*MoBr₄] ( 4 ) [(Cp*MoBr)₂(μ,η³:η³-P₃)(μ,η¹-P₂Br₃)] ( 5 ) and [(Cp*Mo)₂(μ-PBr₂)(μ-PHBr)(μ-Br)₂] ( 6 ). The reaction of 1 with the far stronger oxidizing agent PCl₅ was followed via time- and temperature-dependent ³¹P{¹H} NMR spectroscopy. One of the first intermediates detected at 193 K was [(Cp*Mo)₂(μ,η³:η³-P₃)(μ-PCl₂)₂][PCl₆] ( 8 ) which rearranges upon warming to [(Cp*Mo)₂(μ-PCl₂)₂(μ-Cl)₂] ( 9 ), [(Cp*MoCl)₂(μ,η³:η³-P₃)(μ-PCl₂)] ( 10 ) and [(Cp*Mo)₂(μ,η⁴:η⁴-P₄)(μ-PCl₂)][Cp*MoCl₄] ( 11 ), which could be isolated at room temperature. All complexes were characterized by single-crystal X-ray diffraction, NMR spectroscopy and their electronic structures were elucidated by DFT calculations.     

Synthese und Kristallstruktur des ersten Cp*‐geschützten Cobalttelluridclusters: Darstellung von [(Cp*Co)4(μ3‐Te)4] durch milde Oxidation von [Cp*CoCl]2 mittels Li4Sn2Te6 · 8 en

Synthesis and Crystal Structure of the First Known Cp* Ligated Cobalt Telluride Cluster: Mild Oxidation of [Cp*CoCl]₂ by Li₄Sn₂Te₆ · 8 en to give [(Cp*Co)₄(μ₃‐Te)₄] Oxidation of cobalt(II) complex [Cp*CoCl]₂ (Cp* = pentamethylcyclopentadiene) with binary Zintl polyanion hexatellurodistannate(IV) [Sn₂Te₆]^4– in Li₄Sn₂Te₆ · 8 en (en = 1,2‐diaminoethane) leads to the formation of the first Cp* ligated cobalt telluride cluster [(Cp*Co)₄(μ₃‐Te)₄]. The compound crystallizes as black cuboids that are suitable for X‐ray structural analysis. Space group P 1, lattice dimensions at 203 K: a = 1127.9(2), b = 1156.2(3), c = 1882.3(4) pm, α = 83.27(2), β = 83.24(2), γ = 66.11(1)°, V = 2222.3(9) · 10⁶ pm³, R₁ = 0.0681. The molecular structure of the compound features a Co₄Te₄ heterocubane and thus distributes to the completion of the series of known transition metal chalcogenide heterocubanes.     

Heteroleptic palladium(II) complexes containing N-heterocyclic carbenes and 4-phenyl-1H-1,2,3-triazole: Synthesis,characterization, and catalytic application

Abstract

Reaction of the dimeric N-heterocyclic carbene (NHC) palladium compounds [Pd(μ-Cl)(Cl)(NHC)]₂ with 4-phenyl-1H-1,2,3-triazole gave four mono- and dinuclear complexes 1–4. Mononuclear complexes 1 and 2 [(NHC)PdCl₂(4-phenyl-1H-1,2,3-triazole)] were obtained when the reactions were performed in CH₂Cl₂, whereas dinuclear complexes 3 and 4 [Pd₂(μ-Cl)(μ-4-phenyl-1H-1,2,3-triazole)Cl₂(NHC)₂] were obtained when the reactions were performed in THF in reflux with Et₃N as the base. Further explorations of the catalytic properties of 1–4 for Pd-catalyzed transformations have been performed and these complexes exhibited moderate to high catalytic activities for Suzuki–Miyaura coupling and arylation of benzoxazoles with aryl bromides.     

Metal-induced B—H activation in Cp*Rh,Cp*Ir, (p-cymene)Ru,and (p-cymene)Os half-sandwich complexes containing the 1,2-dicarba-closo-dodecaborane(12)-1,2-dichalcogenolato ligand

The reactivity of the 16e half-sandwich complexes Cp*Rh[E₂C₂(B₁₀H₁₀)] (1a,b), Cp*Ir[E₂C₂(B₁₀H₁₀)] (2a,b) (E = S (a), Se(b)), (p-cymene)Ru[S₂C₂(B₁₀H₁₀)] (3), (p-cymene)Os[S₂C₂(B₁₀H₁₀)] (4) (p-cymene = 1-Me-4-Prⁱ-benzene) towards various alkynes (acetylene, propyne, 3-methoxypropyne, methyl acetylenemonocarboxylate, dimethyl acetylenedicarboxylate, phenylacetylene, ferrocenylacetylene) was studied. The reactions start with an insertion into one of the M—E bonds, followed (except for MeO₂C—CC—CO₂Me) by intramolecular, metal-induced B—H activation, formation of an M—B bond, accompanied by simultaneous transfer of a hydrogen atom from boron via the metal atom to the alkyne. This leads to new complexes with a cisoidor transoid geometry (orientation of the E—C=C unit with respect to the C(1)—B bond). This geometry determines the course of further intramolecular reactions which lead selectively to carboranes mono- or disubstituted in B(3,6) positions. Numerous intermediates and final products were characterized by X-ray analysis in the solid state, and by multinuclear magnetic resonance in solution. First catalytic applications of 1a,b became evident by cyclotrimerization reactions.     

半夹心结构有机金属铱和铑化合物[Cp*M(TmMe)]Cl(M=Ir，Rh；TmMe=三(2-巯基-1-甲基咪唑)硼酸根)的合成与表征

三齿配体三(2-巯基-1-甲基咪唑)硼酸盐[TmMe]K与含有半夹心结构金属铱和铑化合物[Cp*Ir(μ-Cl)Cl]2和[Cp*Rh(μ-Cl)Cl]2反应形成具有18电子结构的配合物[Cp*Ir(TmMe)]Cl(1)和[Cp*Rh(TmMe)]Cl(2).所有的化合物都经过IR,NMR和EA表征,并通过X-射线衍射单晶结构分析测定了配合物2的分子结构.     

Heterometallic (ZrIII)2—Al hydrides [(Cp2Zr)2(μ-H)](μ-H)2AlX2 (X = Cl or Br): preparative synthesis and reactivity. Molecular structure of [(Cp2Zr)2(μ-Cl)](μ-H)2AlCl2

A procedure was developed for the synthesis of trinuclear cyclic (Zr^III)₂—Al hydrides [(Cp₂Zr)₂(μ-H)](μ-H)₂AlX₂ (X = Cl (1a) or Br (1b)). These complexes were prepared in 60–65% yields by the reaction of Cp₂ZrX₂ with LiAlH₄ in the presence of CoBr₂ and tolane. The structures of complexes 1a and 1b and iodide 1c (X = I) were studied by NMR spectroscopy in solvents of different basicities (toluene, THF, and pyridine). Complex 1a is unsolvated and monomeric in all solvents; complex 1b, in toluene and THF; complex 1c, in toluene only. At room temperature, complex 1a does not catalyze hydrogenation of hex-1-ene and does not react with tolane, but reacts with the latter at high temperature to give bis(η⁵-cyclopentadienyl)-2,3,4,5-tetraphenylzirconacyclopentadiene. The reaction of equivalent amounts of complex 1a and HCl produces the [(Cp₂Zr)₂(μ-Cl)](μ-H)₂AlCl₂ complex. The structure of the latter was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2418–2423, November, 2005.     

Synthesis,X-ray structure,in vitro HIV and kinesin Eg5 inhibition activities of new arene ruthenium complexes of pyrimidine analogs

Three new ruthenium(II)-arene complexes of the general formula [{(η⁶-p-cymene)Ru(L)}₂](Cl)₂), where L are monastrol (L¹), ethyl 4-(3-hydroxyphenyl)-6-methyl-2-thioxo-pyrimidine-5-carboxylate (L²) or its 4-bromophenyl analog (L³), have been synthesized and characterized by elemental analysis, ¹H, ¹³C, and 2-D NMR spectroscopy. The X-ray diffraction study of complex 1 showed the presence of a dicationic diruthenium complex where two thioxopyrimidines act as tridentate μ,κN:κ²S ligand, bridging two Ru ions through the pyrimidine nitrogen and sulfur atoms. All new complexes were evaluated in vitro for their antiviral activity against the replication of HIV-1 and HIV-2 in MT-4 cells using MTT assay. Additionally, complexes 1–3 were screened for their inhibitory activity against the ATPase enzyme and the motor-protein Kinesin Eg5. Complex 1 was found to inhibit microtubule-stimulated ATPase activity of kinesin of IC₅₀ = 30 μM (monastrol, IC₅₀ = 10 μM).     

Hydrogen Generation by Water Reduction with [Cp*2Ti(OTf)]: Identifying Elemental Mechanistic Steps by Combined In Situ FTIR and In Situ EPR Spectroscopy Supported by DFT Calculations

A detailed mechanism of hydrogen production by reduction of water with decamethyltitanocene triflate [Cp*₂Ti^III(OTf)] has been derived for the first time, based on a comprehensive in situ spectroscopic study including EPR and ATR‐FTIR spectroscopy supported by DFT calculations. It is demonstrated that two H₂O molecules coordinate to [Cp*₂Ti^III(OTf)] subsequently forming [Cp₂*Ti^III(H₂O)(OTf)] and [Cp*Ti^III(H₂O)₂(OTf)]. Triflate stabilizes the water ligands by hydrogen bonding. Liberation of hydrogen proceeds only from the diaqua complex [Cp*Ti^III(H₂O)₂(OTf)] and involves, most probably, abstraction and recombination of two H atoms from two molecules of [Cp*Ti^III(H₂O)₂(OTf)] in close vicinity, which is driven by the formation of a strong covalent Ti? OH bond in the resulting final product [Cp*₂Ti^IV(OTf)(OH)].     

Anion-dependent structural diversity of cadmium(II) complexes: synthesis,crystal structures,luminescence properties,and unusual C-H/σ supramolecular interactions involving σ-aromatic M2X2 cores

Four complexes based on N,N′-bis(2-pyridylmethylene)-1,3-propanediamine (L) and different Cd(II) salts have been synthesized and characterized by single-crystal X-ray diffraction analysis. The complexes are [Cd₂(L)₂(μ-Cl)₂](ClO₄)₂ (1), [Cd₂(L)₂(μ-Br)₂](ClO₄)₂ (2), [Cd(L)I](ClO₄) (3), and [Cd(L)(NCS)₂] (4). L exhibits the same coordination mode in 1–4. The radius of each anion plays a role in affecting the structures and luminescent intensities of the final products. CdCl₂, CdBr₂, and CdI₂ react with L to produce chloride or bromido-bridged binuclear complexes and mononuclear iodido complex, respectively, whereas an unusual mononuclear trigonal prismatic (TP) 4 is obtained when thiocyanate was used as a coligand. Photoluminescence properties of all the complexes show that the trend of fluorescence intensity is 1 > 4 > 2 > 3. All four complexes exhibit different supramolecular interactions such as C–H/σ, π–π, and C–H/π and hydrogen bonding interactions. The experimental findings are complemented by density functional theory (DFT) calculations.     

Synthesis, spectra and electrochemistry of dinitro- bis -2-(phenylazo)pyrimidine ruthenium(II). Nitro*#x2014;nitroso derivatives and reactivity of the electrophilic nitrosyl centreruthenium(II). Nitro*#x2014;nitroso derivatives and reactivity of the electrophilic nitrosyl centre

Silver-assisted aquation of bluecis-trans-cis-RuCl₂(Raapm)₂ (1a-1e) leads to the synthesis of solvento species, blue-violetcis-trans-cis-[Ru(OH₂)₂(Raapm)₂](ClO₄)₂ [Raapm =p-R-C₆H₄-N=N-C₄H₃-NN, (2a-2e), abbreviated as N,N′-chelator, where N(pyrimidine) and N(azo) represent N and N′ respectively; R = H (a),p-Me (b),p-Cl (c),m-Me (d),m-Cl (e) that react with NO₂ in warm EtOH to give violet dinitro complexes of the type, Ru(NO₂)₂(Raapm)₂ (3a-3e). The nitrite complexes are useful synthons of electrophilic nitrosyls, and on triturating the dinitro compounds with conc. HClO₄, nitro-nitrosyl derivatives are isolated. The solution structure and stereoretentive transformation in each step have been established from¹H NMR results. The compounds are redox active and display one metal-centred oxidation and successive ligand-based reductions. The v (NO) > 1900 cm^-1 strongly suggests the presence of linear Ru-N-O bonding. The electrophilic behaviour of metal-bound nitrosyl has been proved in one case by reacting with a bicyclic ketone, camphor, containing an active methylene group and an arylhydrazone with an active methine group. Diazotization of primary aromatic amines with strongly electrophilic mononitrosyl complexes in acetonotrile and dichloromethane solutions has been thoroughly studied.     

Synthesis and structure of some ruthenium-rhenium heterodinuclear complexes and their catalytic activity in the addition of carboxylic acids to phenylacetylene

The salt elimination reaction of Na[Re(CO)₅] with Cp*Ru(dppm)Cl, CpRu(dppm)Cl or CpRu(CO)₂Cl afforded the heterodinuclear species Cp*Ru(μ-CO)₂(μ-dppm)Re(CO)₃, Cp(CO)Ru(μ-dppm)Re(CO)₄, or Cp(CO)₂RuRe(CO)₅, respectively, in moderate yields. An orthometallated species, Cp*(CO)Ru(μ-H)[μ-PhP(C₆H₄)CH₂PPh₂]Re(CO)₃, was also obtained from the first reaction. All these heterodinuclear products have been characterised crystallographically. They also showed good catalytic activity for the addition of carboxylic acids to phenylacetylene to afford the anti-Markovnikov products selectively.