Synthesis,Crystal Structures,and Urease Inhibitory Activities of Three Novel Thiocyanato‐bridged Polynuclear Schiff Base Cadmium(II) Complexes

Three novel thiocyanato‐bridged polynuclear cadmium(II) complexes, [Cd(HL1)(NCS)₂(μ_1,3‐NCS)]_n ( 1 ), [CdL2(μ_1,3‐NCS)₂]_n ( 2 ), and [CdL3(μ_1,3‐NCS)₂]_n ( 3 ) (L1 = N‐methyl‐N′‐(1‐pyridin‐2‐ylmethylidene)ethane‐1,2‐diamine, L2 = 2‐(cyclopropyliminomethyl)‐6‐methoxyphenol, L3 = 2‐(cyclopentyliminomethyl)‐6‐methoxyphenol), have been synthesized and structurally characterized by elemental analysis, IR spectra and single‐crystal X‐ray diffraction. Each cadmium(II) atom in the complexes is in an octahedral coordination. The urease inhibitory activities of the complexes were evaluated. All of them showed potent inhibitions against jack bean urease.     

Solvent‐controlled Syntheses and Crystal Structures of a Pair of Novel Thiocyanate‐bridged Copper(II) Complexes Constructed from 4‐Bromo‐2‐(cyclopropyliminomethyl)phenolate

A pair of novel thiocyanate‐bridged polynuclear copper(II) complexes, [Cu₂(BCP)₂(NCS)₂]_n ( 1 ) and [Cu₂(BCP)₂(MeOH)(NCS)₂]₂ ( 2 ) [BCP = 4‐bromo‐2‐(cyclopropyliminomethyl)phenolate], have been obtained from an identical synthetic procedure and starting materials using solvents as the only independent variable. Complex 1 was synthesized and crystallized using EtOH as the solvent, while complex 2 was synthesized and crystallized using MeOH as the solvent. Both complexes show novel self‐assembled supramolecular structures in their crystals as elucidated by X‐ray analyses. The polymeric dinuclear complex 1 contains [Cu₂(BCP)₂(NCS)₂] units as the building blocks, crystallizes in the Pbca space group. The monomeric tetranuclear complex 2 contains [Cu₂(BCP)₂(MeOH)(NCS)₂] units as the building blocks, crystallizes in the P2₁/n space group.     

Spray‐Coating of Catalytically Active MOF–Polythiourea through Postsynthetic Polymerization

A UiO‐66‐NCS MOF was formed by postsynthetic modification of UiO‐66‐NH₂. The UiO‐66‐NCS MOFs displays a circa 20‐fold increase in activity against the chemical warfare agent simulant dimethyl‐4‐nitrophenyl phosphate (DMNP) compared to UiO‐66‐NH₂, making it the most active MOF materials using a validated high‐throughput screening. The ?NCS functional groups provide reactive handles for postsynthetic polymerization of the MOFs into functional materials. These MOFs can be tethered to amine‐terminated polypropylene polymers (Jeffamines) through a facile room‐temperature synthesis with no byproducts. The MOFs are then crosslinked into a MOF–polythiourea (MOF–PTU) composite material, maintaining the catalytic properties of the MOF and the flexibility of the polymer. This MOF–PTU hybrid material was spray‐coated onto Nyco textile fibers, displaying excellent adhesion to the fiber surface. The spray‐coated fibers were screened for the degradation of DMNP and showed durable catalytic reactivity.     

Two furo­pyridine complexes of nickel(II) iso­thio­cyanate

Pyridine fused with a furan ring (fupy), and its di­methyl derivative, have been used for the first time as ligands to synthesize potentially new Werner clathrates. The extended aromatic system of pyridine‐like ligands influences considerably the molecular structure of prepared nickel complexes. The molecular structure of tetrakis­(furo­[3,2‐c]­pyridine)­bis(iso­thio­cyanato)­nickel(II) tetra­hydro­furan (THF) solvate, [Ni(NCS)₂(C₇H₅NO)₄]·C₄H₈O or [Ni(NCS)₂(fupy)₄]·THF, (I), reveals a `four‐blade propeller' arrangement of ligands, with the angles between the fupy planes and the basal octahedron plane spanning the range 38.7–55.3°. These angles are much larger (69.9–78.8°) in the centrosymmetric complex tetrakis(2,3‐di­methyl­furo­[3,2‐c]­pyridine)­bis­(iso­thio­cyanato)nickel(II) 6.6‐hydrate, [Ni(NCS)₂(C₉H₉NO)₄]·6.6H₂O or [Ni(NCS)₂(Me₂fupy)₄]·6.6H₂O, (II), in which crystallographically imposed inversion symmetry is present.     

Poly[bis(N‐methylformamide)tetra‐μ‐thiocyanato‐manganese(II)mercury(II)]

The title complex, [MnHg(NCS)₄(C₂H₅NO)₂]_n, consists of slightly distorted MnN₄O₂ octa­hedra and HgS₄ tetra­hedra. Each Mn^II cation is bound to four N atoms of the NCS groups and two O atoms of the N‐methyl­formamide (NMF) ligands in a cis configuration. Each Hg^II cation is coordinated to four S atoms of NCS groups. Each pair of Mn^II and Hg^II cations is connected by an –NCS– bridge, forming an infinite three‐dimensional –Mn—NCS—Hg– network.     

Synthesis,Crystal Structure,and Spectral Properties of Two Manganese(II) and Zinc(II) Complexes with 3,4‐Dimethyl‐5‐(2‐pyridyl)‐1,2,4‐triazole

Two complexes, cis‐[MnL₂(NCS)₂] ( 1 ) and cis‐[ZnL₂(NCS)₂] ( 2 ) with asymmetrical substituted triazole ligands [L = 3,4‐dimethyl‐5‐(2‐pyridyl)‐1,2,4‐triazole], were synthesized and characterized by elemental analysis, UV/Vis and FT‐IR spectroscopy as well as thermogravimetric analyses (TGA), powder XRD, and single‐crystal X‐ray diffraction. In the complexes, each L molecule adopts a chelating bidentate mode by the nitrogen atoms of pyridyl and triazole. Both complexes have a similar distorted octahedral [MN₆] core (M = Mn²⁺ and Zn²⁺) with two NCS^– ions in the cis position.     

Dipotassium di‐μ‐iso­thio­cyanato‐κ4N:S‐bis­[(N‐salicyl­idene‐dl‐valinato‐κ3O,N,O′)­cuprate(II)]

The title compound, K₂[Cu₂(NCS)₂(C₁₂H₁₃NO₃)₂], consists of two K⁺ cations and (N‐salicyl­idene‐d ‐valinato)­cop­per(II) and (N‐salicyl­idene‐l ‐valinato)cop­per(II) coordination units con­nected through three‐atom thio­cyanate (μ‐NCS) bridges into a centrosymmetric dianion. The Cu^II atom adopts a square‐pyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging ligand (μ‐NCS) in the basal plane. The axial position is occupied by the thio­cyanate S atom of a symmetry‐related ligand at an apical distance of 2.9332 (10) Å. Coulombic interactions between six‐coordinated K⁺ ions and the heteroatoms of neighbouring dimeric anions leads to the formation of one‐dimensional chains of mol­ecules parallel to [010]. The superposition of the normals of the pyramidal base planes in a direction close to [001] indicates possible π–π interactions between neighbouring units.     

catena‐Poly[potassium [copper(II)‐μ‐isothiocyanato‐μ‐N‐salicylidene‐β‐alaninato(2–)]]

The title polymeric compound, catena‐poly­[dipotassium [bis­[μ‐N‐salicyl­idene‐β‐alaninato(2−)]‐κ⁴O,N,O′:O′′;κ⁴O′′:O,N,O′‐dicopper(II)]‐di‐μ‐iso­thio­cyanato‐κ²N:S;κ²S:N], {K[Cu(NCS)(C₁₀H₉NO₃)]}_n, consists of [iso­thio­cyanato(N‐salicyl­idene‐β‐alaninato)copper(II)]⁻ anions connected through the two three‐atom thio­cyanate (μ‐NCS) and the two anti,anti‐μ‐­carboxyl­ate bridges into infinite one‐dimensional polymeric anions, with coulombically interacting K⁺ counter‐ions with coordination number 7 constrained between the chains. The Cu^II atoms adopt a distorted tetragonal–bipyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging μ‐NCS ligand in the basal plane. The first axial position is occupied by a thio­cyanate S atom of a symmetry‐related μ‐NCS ligand at an apical distance of 2.9770 (8) Å, and the second position is occupied by an O atom of a bridging carboxyl­ate group from an adjacent coordination unit at a distance of 2.639 (2) Å.     

Thiocyanate‐free ruthenium(II) tetrabenzoporphyrin sensitizers for photoelectrochemical cell: A DFT/TD‐DFT probe for stability of axial donor ligands

Although previously studied [(HOOC)₄(TBPor)Ru(NCS)₂]^2– ( A ; TBPor = tetrabenzoporphrin) avoided the intrinsic π‐stacking aggregation of planar metallophorphryins via incorporating two axial ligands, these isothiocyanato groups are believed to be the weakest part of the sensitizer while operating in dye‐sensitized solar cells (DSSCs). In this work, a series of thiocyanate‐free ruthenium porphyrin complexes featuring with phenyl/substituted‐phenyl axial groups, [(HOOC)₄(TBPor)Ru(L′)₂]^2– (L′ = Ph ( 1 ), PhF₂ ( 2 ), PhCl₂ ( 3 ), PhBr₂ ( 4 ), and PhI₂ ( 5 )), have been examined using density functional theory (DFT) and time‐dependent DFT (TD‐DFT). Both analyses of electronic structures and calculations of interaction energies demonstrate that the Ru‐L′ interaction in 1 – 5 is significantly enhanced relative to the Ru‐NCS in A , which will raise chemical stability of the former in DSSCs. Single‐electron oxidation mechanism has been proposed. Oxidation potentials (E⁰) are increased by 0.2–0.6 V when changing axial groups from NCS to Ph/PhX₂. The spin‐orbit coupling (SOC) relativistic effects can be negligible in computing E⁰ values. TD‐DFT calculations show that 1 – 5 have more intense Q band in the visible region than A does. Taken together, high chemical stability, suitable oxidation potential and expanding absorption spectra would allow for potential applications of the thiocyanate‐free sensitizers in DSSCs. © 2016 Wiley Periodicals, Inc.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalyse von (n‐Bu4N)2[Os(NCS)6] und (n‐Bu4N)3[Os(NCS)6]

Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of ( n ‐Bu₄N)₂[Os(NCS)₆] and ( n ‐Bu₄N)₃[Os(NCS)₆] By tempering the solid mixture of the linkage isomers (n‐Bu₄N)₃[Os(NCS)_n(SCN)_6–n] n = 0–5 for a longer time at temperatures increasing from 60 to 140 °C the homoleptic (n‐Bu₄N)₃[Os(NCS)₆] is formed, which on oxidation with (NH₄)₂[Ce(NO₃)₆] in acetone yields the corresponding Os^IV complex (n‐Bu₄N)₂[Os(NCS)₆]. X‐ray structure determinations on single crystals of (n‐Bu₄N)₂[Os(NCS)₆] (1) (triclinic, space group P 1, a = 12.596(5), b = 12.666(5), c = 16.026(5) Å, α = 88.063(5), β = 80.439(5), γ = 88.637(5)°, Z = 2) and (n‐Bu₄N)₃[Os(NCS)₆] ( 2 ) (cubic, space group Pa 3, a = 24.349(4) Å, Z = 8) have been performed. The nearly linear thiocyanate groups are coordinated with Os–N–C angles of 172.3–177.7°. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constant f_d(OsN) is 2.3 ( 1 ) and 2.10 mdyn/Å ( 2 ).     

Synthesis and Characterization of Heteroleptic Ru(II) Complexes Based on 4,4′‐Bis((E)‐styryl)‐2,2′‐bipyridine as Ancillary Ligand and Application for Dye‐Sensitized Solar Cells

Heteroleptic Ru(II) complexes were designed based on 4,4′‐bis((E)‐styryl)‐2,2′‐bipyridine (bsbpy) as an ancillary ligand for dye‐sensitized solar cells (DSSCs), and those Ru(II) sensitizers, [Ru(L)(bsbpy)(NCS)₂][TBA] (TBA; tetrabutylammonium), were synthesized according to a typical one‐pot reaction of [RuCl₂(p‐cymene)]₂ with the corresponding anchoring ligands (where L = 4,4′‐dicarboxy‐2,2′‐bipyridine (dcbpy), 4,4′‐bis((E)‐carboxyvinyl)‐2,2′‐bipyridine (dcvbpy), 4,7‐dicarboxy‐1,10‐phenanthroline (dcphen), or 4,7‐bis((E)‐carboxyvinyl)‐1,10‐phenanthroline (dcvphen)). The new Ru(II) dyes, [Ru(L)(bsbpy)(NCS)₂][TBA] that incorporated vinyl spacer(s) into ancillary and/or anchoring ligand displayed red‐shifted bands over the overall UV/VIS region relative to the absorption spectra of N719 . A combination of bsbpy ancillary and dcphen anchoring ligand showed the best result for the overall power conversion efficiency (η); i.e., a DSSC fabricated with [Ru(dcphen)(bsbpy)(NCS)₂][TBA] exhibited a power conversion efficiency (η) of 2.98% (compare to N719 , 4.82%).     

One‐dimensional polymeric chain structure of bis­(aniline)­di­thio­cyanato­cadmium(II)

In the title compound, catena‐poly­[[bis­(aniline‐N)cadmium(II)]‐di‐μ‐thio­cyanato‐S:N;N:S], [Cd­(SCN)₂­(C₆H₇N)₂], the Cd^II atom lies on an inversion centre and is in a distorted octahedral geometry. The coordination sphere contains two thio­cyanate (SCN) S atoms, two iso­thio­cyanate (NCS) N atoms and two aniline N atoms. The six‐coordinated Cd atoms run parallel to the b axis and are doubly bridged with neighbouring Cd atoms by SCN and NCS ligands. Thus, this complex has a one‐dimensional coordination polymeric chain structure in which the aniline ligand is in the trans conformation.     

Synthesis of 3‐Halogenated Flavonoids via Electrophile‐Promoted Cyclization of 2‐(3‐Aryl‐2‐propynoyl)anisoles

Treatment of 2‐(1‐aryl‐3‐propynoyl) anisoles 1 with N‐chlorosuccinimide (NCS) or N‐bromosuccinimide (NBS) gave the 3‐halogenated flavones and their related molecules in moderate yields.     

离子液体-水介质中离子液体负载TEMPO催化选择氧化合成脂肪醇羟基芳香醛和酮

由于脂肪醇羟基和苄醇羟基具有相同的氧化反应活性,所以当分子内同时含有脂肪醇羟基和苄醇羟基时,很难选择氧化苄醇羟基合成含脂肪醇羟基的芳香醛或酮。本文报道了在离子液体-水介质中,NCS/NaBr/IL-TEMPO（离子液体负载TEMPO）催化氧化合成含有脂肪醇羟基的芳香醛、酮的方法,反应条件温和,选择性好,收率高,且离子液体和催化剂可以循环使用。     

A Novel 4, 4'‐Azopyridine‐Bridged Manganese Polymer: Quasi Two‐dimensional Structure and Magnetic Properties

A novel coordination polymer {[Mn(azpy)(NCS)₂(MeOH)₂] · azpy}_n( 1 ) (azpy = 4, 4'‐azopyridine), has been synthesized and characterized by X‐ray diffraction. It consists of a quasi two‐dimensional network structure constructed from 1‐D chains of [Mn(azpy)(NCS)₂(MeOH)₂]_n connected by hydrogen bonds, which creates about 13.6 Å × 17.1 Å of channels. The coordination sphere of the manganese(II) ion is a distorted octahedron. The determination of the variable temperature magnetic susceptibilities (5—300 K) shows the existence of a very weak antiferromagnetic interaction with a J value of —0.03 cm^—1.     

Effect of Chelate Ring Size in Iron(II) Isothiocyanato Complexes with Tetradentate Tripyridyl‐alkylamine Ligands on Spin Crossover Properties

Iron(II) complexes of the type [Fe(L)(NCS)₂] with tetradentate ligands L are well known to show spin crossover properties. However, this behavior is quite sensitive in regard to small changes of the ligand system. Starting from the thoroughly investigated complex [Fe(tmpa)(NCS)₂] [tmpa = tris(2‐pyridylmethyl)amine, also abbreviated as tpa in the literature] we modified the ligand by increasing systematically the chelate ring sizes from 5 to 6 thus obtaining complexes [Fe(pmea)(NCS)₂], [Fe(pmap)(NCS)₂], and [Fe(tepa)(NCS)₂] [pmea = N,N‐bis[(2‐pyridyl)methyl]‐2‐(2‐pyridyl)ethylamine, pmap = N,N‐bis[2‐(2‐pyridyl)ethyl]‐(2‐pyridyl)methylamine, and tepa = tris[2‐(2‐pyridyl)ethyl]amine]. All complexes were structurally characterized and spin crossover properties were investigated using Mößbauer spectroscopy, magnetic measurements, and IR/Raman analyses. The results demonstrated that only the iron complexes with tmpa and pmea showed spin crossover properties, whereas the complexes with the ligands pmap and tepa only formed high spin complexes. Furthermore, DFT calculations supported these findings demonstrating again the strong influence of ligand environment. Herein the effect of increasing the chelate ring sizes in iron(II) isothiocyanato complexes with tetradentate tripyridyl‐alkylamine ligands is clearly demonstrated.     

Syntheses and Characterizations of Novel One-dimensional Coordination Polymers Self-assembled from Co(NCS)_2 and Flexible Diester-bridged Pyridine-based Ligands

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Synthesis of Amphiphilic RuII Heteroleptic Complexes Based on Benzo[1,2‐b:4,5‐b′]dithiophene: Relevance of the Half‐Sandwich Complex Intermediate and Solvent Compatibility

The detailed synthesis and characterization of four ruthenium(II) complexes [RuLL′(NCS)₂] is reported, in which L represents a 2,2′‐bipyridine ligand functionalized at the 4,4′ positions with benzo[1,2‐b:4,5‐b′]dithiophene derivatives (BDT) and L′ is 2,2′‐bipyridine‐4,4′‐dicarboxylic acid unit (dcbpy) (NCS=isothiocyanate). The reaction conditions were adapted and optimized for the preparation of these amphiphilic complexes with a strong lipophilic character. The photovoltaic performances of these complexes were tested in TiO₂ dye‐sensitized solar cell (DSSC) achieving efficiencies in the range of 3–4.5 % under simulated one sun illumination (AM1.5G).     

catena‐Poly[[diisothio­cyanato­cad­mium(II)]‐bis­[μ‐1,3‐bis­(1,2,4‐triazol‐1‐ylmeth­yl)benzene‐κ2N4:N4′]]: a double‐chain coordination polymer

The coordination geometry of the Cd^II atom in the title complex, [Cd(NCS)₂(C₁₂H₁₂N₆)₂]_n or [Cd(NCS)₂(mbtz)₂]_n, where mbtz is 1,3‐bis­(1,2,4‐triazol‐1‐ylmeth­yl)benzene, is a distorted compressed octa­hedron in which the Cd^II atom lies on an inversion centre, coordinated by four N atoms from the triazole rings of four mbtz ligands and two N atoms from two monodentate NCS⁻ ligands. The structure is polymeric, with 24‐membered spiro‐fused rings extending along [100] and with the 24‐membered ring containing two inversion‐related mbtz mol­ecules.     

Selective Halogenation Using an Aniline Catalyst

Electrophilic halogenation is used to produce a wide variety of halogenated compounds. Previously reported methods have been developed mainly using a reagent‐based approach. Unfortunately, a suitable “catalytic” process for halogen transfer reactions has yet to be achieved. In this study, arylamines have been found to generate an N‐halo arylamine intermediate, which acts as a highly reactive but selective catalytic electrophilic halogen source. A wide variety of heteroaromatic and aromatic compounds are halogenated using commercially available N‐halosuccinimides, for example, NCS, NBS, and NIS, with good to excellent yields and with very high selectivity. In the case of unactivated double bonds, allylic chlorides are obtained under chlorination conditions, whereas bromocyclization occurs for polyolefin. The reactivity of the catalyst can be tuned by varying the electronic properties of the arene moiety of catalyst.