A new quinoline-based chemosensor in ratiometric sensing of Hg2+ ions

A new quinoline-based chemosensor 1 has been designed and synthesised. Its metal ion-binding properties have been documented in organic and aqueous organic solvents. While chemosensor 1 recognises Hg²⁺ ions (K _a = 2.15 × 10⁴ M^? 1) by exhibiting ratiometric change in emission in CHCl₃/CH₃OH (1:1, v/v), under similar condition both Zn²⁺ and Cd²⁺ ions are sensed by significant non-ratiometric increase in emission with measurable red shift. In DMSO/H₂O (5:95, v/v), the sensor 1 exhibits a greater selectivity towards Hg²⁺ ions (K _a = 9.20 × 10³ M^? 1) over the other metal ions examined.     

1,3-Bis(pyren-1-yliminomethyl)calix[4]arene as a selective fluorescent turn-on sensor for mercury(II) ion

A novel calixarene-based diimine, 1,3-bis(pyren-1-yliminomethyl)calix[4]arene (5), serves as a turn-on-type fluorescent sensor, which selectively detects Hg²⁺ in THF/H₂O (99:1, v/v) in the presence of various other metal ions. Such selectivity is not seen with half salen 1 derived from salicylaldehyde and 1-aminopyrene. ¹H NMR analysis reveals that it is a chemodosimetric sensor based on its hydrolysis mediated by Hg²⁺ to release 1-aminopyrene molecules as fluorescent chromophores.     

Detection of Sulfur Dioxide Using a Piezoelectric Quartz Crystal Microbalance

Abstract

Sulfur dioxide was detected and determined in air by a piezoelectric quartz crystal sensor coated with 4-aminoantipyrine 1-hydroxyetil-2-heptadecenyl imidazol (amine 220) solution (1:1 v/v in chloroform). The analytical response curve is linear over the concentration range from 0.70 to 5.0 ppm of SO₂. Good linearities (r = 0.9990, 0.9995 and 0.9968) and sensitivities (18.0, 33.4 and 50.7 Hz/ppm) were found, respectively for exposure times of 30, 60 and 90 seconds. The sensor can be used for more than six months without loss in sensitivity and presented good reversibility and reproducibility. Among some possible interferents tested, only nitrogen dioxide and moisture caused major frequency changes.     

A rapid selective colorimetric and ‘On–Off’ fluorimetric sensor for detecting Cu2+ ions in aqueous media based on a simple bis-schiff-base derivative

A simple colorimetric and fluorimetric ‘On–Off’ sensor L (3,3′-dimethyl -[1,1′-biphenyl]-4,4′-diyl)bis(azanylylidene)bis(methanylylidene)bis(naphthalen-2-ol) for Cu²⁺ ions bearing o-tolidine substituents has been designed and synthesised, and exhibits significant fluorimetric and colorimetric response for Cu²⁺ in DMSO/H₂O (8:2, v/v) HEPES buffer (pH 7.2) solution. The detection limit of the sensor towards Cu²⁺ is 7.25 × 10^? 8 M and the association constant K_a of 9.86 × 10⁴ M^? 1 was determined. Furthermore, other anions, including Fe³⁺, Hg²⁺, Ag⁺, Ca²⁺, Co²⁺, Ni²⁺, Cd²⁺, Pb²⁺, Zn²⁺, Cr³⁺ and Mg²⁺ have almost no influence on the probe's behaviour. Test strips based on the sensor L were fabricated, which could act as convenient and efficient Cu²⁺ test kits.     

Kinetic investigations on interaction of carbon monoxide with RuIICl2(PPh3)3 in mixed aqueous medium

Kinetics, equilibrium and thermodynamics of interaction of CO with RuCl₂(PPh₃)₃ (1) have been investigated in 1:1(v/v) water — 1,4-dioxan mixture in which 1 dissociates to RuCl₂(PPh₃)₂ (1a), by losing a coordinated PPh₃. The kinetics of complexation of (1a) with CO to form RuCl₂(CO)(PPh₃)₂ (2) indicated first order dependence in [1a] and [CO]. The thermodynamic parameters for the formation of 2 were determined.This revised version was published online in December 2005 with corrections to the Cover Date.     

A highly selective and sensitive dual-channel chemosensor for cyanide based on sulfahydrazone derivative

A colorimetric and fluorescent cyanide probe bearing naphthol and sulfahydrazone groups has been designed and synthesized. This structurally simple probe displays a rapid response and high selectivity for cyanide in DMSO/EtOH (v/v = 2:8) solution. The addition of CN^? to the sensor p-toluenesulfonyl-2-hydroxy-1-naphthylhydrazone (L3) induced a remarkable color change from pale-yellow to yellow, and green fluorescence changed to yellow. The ¹H NMR titration and DFT calculations suggested that the selective sensing process is based on a nucleophilic addition reaction of cyanide to imine. Test strips based on sensor L3 were fabricated, which could act as a convenient and efficient test kit to detect CN^? for “in-the-field” measurements.     

A bifunctional 2,2′:6′,2″-terpyridine-based ligand for ratiometric Cu(II) sensing

Synthesis and characterization of the bifunctional sensor receptor ligand N-([2,2′:6′,2″-terpyridine]-4′-yl)methyl)-N-propylacrylamide (1) and the model ligand N-([2,2′:6′,2″-terpyridine]-4′-yl)methyl)-N-propylisobutyramide (2) are described. Ligand 1 is a receptor for Cu(II) that is copolymerizable with N-isopropylacrylamide giving a ratiometric sensor of weakly bound Cu(II) in environmental waters. Ligand 2 is a model for copolymerized 1 whereby the reactive acrylamide group is replaced by isobutyramide. Solution speciation of complexes of Cu(II) and Zn(II) with 2 were investigated spectroscopically and their solid-state structures were studied through single-crystal X-ray diffraction. Solution UV–vis and fluorescence studies show a preference of 2 toward Cu(II) over Na(I), Zn(II), Cu(II), Co(II), Mn(II), Ni(II), Cd(II), and Pb(II) in accord with the Irving–Williams series and other coordination principles. Solution speciation determined in a weakly coordinating aqueous-organic (60?:?40 DMF/H₂O) medium indicates 1?:?1 Cu(II):2 binding as desired in that formation of [Cu(2)₂]²⁺ would crosslink the polymer sensor. The crystal structures of [Cu(2)(NO₃)₂] and [Zn(2)(NO₃)₂]·MeOH·1/2Et₂O display distorted octahedral geometries where 2 coordinates meridionally and two nitrate groups occupy the remaining sites around the metal center.     

Reactions of pyrrole-2,5-dicarbaldehyde with 2-aminodiphenylamine in the presence of nickel and cobalt trimethylacetates

The reactions of pyrrole-2,5-dicarbaldehyde (1) with 2-aminodiphenylamine (3) taken in a ratio of 1 : 2 in the presence of polinuclear nickel(ii) and cobalt(ii) trimethylacetate complexes were studied in MeCN. The reaction with Ni₉(HOOCCMe₃)₄(₄-OH)₃(₃-OH)₃(OOCCMe₃)₁₂ (2) afforded the mononuclear complex Ni(OOCCMe₃)₂[(PhHN)C₆H₄NHCHC₄H₂NCHNC₆H₄(NHPh)] (4) with a new ligand, which is the product of condensation of one molecule 1 with two molecules 3 and contains two NHPh groups. By contrast, the reaction with the polymeric complex [Co(OH) _n (OOCCMe₃)_2–n ] _x (5, n = 0.05—0.1) gave rise to the tetranuclear complex Co₄(₄-O)(-OOCCMe₃)₄L₂ (6), where L is, apparently, the product of further oxidation of Schiff"s base to the benzimidazole derivative. The structures of compounds 4 and 6 were established by X-ray diffraction analysis.     

Substituted metal carbonyls. Part 25: Unidentate,intramolecular, and intermolecular bridging modes of 1,1′-bis(diphenylphosphino)ferrocene inM 3S2(CO)9 (M = Fe,Ru) cluster derivatives

Carbonyl exchange of Fe₃(₃-S)₂(CO)₉ wioth1,1-bis(diphenylphosphino)ferrocene (dppf) in refluxing THF gives a cluster ligand with a pendant phosphine moiety, Fe₃(₃-S)₂(CO)₈ (gn¹-Ph₂PlC₅H₄)Fe(C₅H₄)P⁴ MePh₂)]1 ^–,4. Addition of 1 to AuCl(SMe₂) gives ClAu(-dppf) Fe₄(₃-S)₂(CO)₈,8 (45%). Spectroscopic evidence is also obtained for (OC)₈ (₃-S)₂Fe₃(-dppf) Os₃(CO)₁₁,7 and PdCl₂[(-dppf)Fe₃(₃-D)₂(CO)₈]₂,9, from1 and Os₃(CO)₁₁(CH₃CN) and PdCl₂CN)₂, respectively. Crystal data dor3: space group P2₁/n,a = 10.891(3) Å,b = 19.939(3) Å,c = 20.443(2) Å, 100.17(2)°.Z = 4, 3917 reflections,R = 0.049.     

Metal complexes of indole-3-acetic acid: synthesis,crystal structures,and Pb2+ chemosensing by cation-exchange reaction

Two binuclear complexes [Cu₂(IA)₄(DMSO)₂]·CH₃OH (1), [Cd₂(IA)₂(phen)₂I₂] (2), and one 1-D {[Pb₂(IA)₄]·CH₃OH}_n (3) (IAH = indole-3-acetic acid, phen = 1,10-phenanthroline) have been prepared and characterized by single crystal X-ray diffraction. Both 1 and 2 are binuclear wherein the central Cu ions are bridged by IA in 1, while Cd ions are bridged by I^? in 2. Complex 3 has a 1-D chain structure based on secondary building units (SBUs) of [Pb₂(IA)₄]. The three complexes show strong fluorescence emissions, and chemosensor behaviors for metal cations are investigated in mixed DMF/H₂O (1?:?9 v/v) solvent. The results reveal that 2 shows effective sensing to Pb²⁺. The mechanism of the detection to Pb²⁺ can be attributed to cation-exchange reaction between cadmium and lead ions.     

Clusters containing ynamine ligands. 4. The synthesis and characterizations of ReMn(CO)8 [μ-MeC2NMe2] and ReMn(CO)7 [μ-MeCC(NMe2)C(NMe2)CMe] and the development of a bonding model for the coordination of ynamines to M2(CO)8 clusters

The compound ReMn(CO)₈ (-MeC₂NMe₂),2 was obtained in 11% yield by the decarbonylation of ReMn(CO)₁₀ with Me₃NO followed by reaction MeC₂NMe₂. Compound2 will add one equivalent of MeC₂NMe₂ at 25°C to yield the mixed metal complex ReMn(CO)₇ [-C(Me) C(NMe₂) C(NMe₂) C(Me)],3 in 7% yield. Compounds2 and3 were characterized by IR,¹H NMR, and single crystal x-ray diffraction analyses. Compound2 exists as two isomers. Each isomer contains an asymmetric bridging ynamine ligand. The principal isomer has the amine-substituted carbon atom coordinated to the manganese atom. The minor isomer has the amine-substituted carbon atom coordinated to the rhenium atom. In compound3 the two ynamines have been coupled in a head-to-head fashion to produce a ferrole-like structure in which the coupled ligands are -bonded to the manganese atom. Extended Hückel molecular orbital calculations were performed on the parent complex Re₂(CO)₈ (-MeC₂NMe₂),1 to try to understand the reasons for the preferred asymmetric coordination of the ynamine ligand in1 and2. It was found that the asymmetric coordination permits a strong stabilizing interaction between the one of the * orbitals of the ligand and the metallic orbital that is principally responsible for the formation of the metal-metal bond. Crystal Data: for2: space group=P2₁/c,a=9.740(1)Å,b=11.293(2)Å,c=15.483(3)Å, =97.46(1)°,Z=4, 1876 reflections,R=0.026; for3: space group=Pca2₁,a=17.541(2)Å,b=8.441(1)Å,c=14.033(3)Å,Z=4, 1335 reflections,R=0.022.     

Synthesis and Characterization of Tetraosmium Carbonyl Complexes Containing a Bridging CO2 Ligand

Treatment of (thd)H (thd=2,2,6,6-tetramethyl-3,5-heptandionate) with excess Os₃(CO)₁₂ in an autoclave at 180°C gives the formation of a brown metal chain complex [Os₂(CO)₅(thd)₂]₂ (1) and a yellow CO₂ cluster complex [Os₄(-H)(-CO₂)(thd)(CO)₁₃] (2) in low yields. Complex 2 was fully identified by a combination of spectroscopic methods and X-ray diffraction study, showing a unique CO₂ ligand bridging a triosmium metal fragment, Os₃(-H)(CO)₁₀ and a monometallic osmium fragment, Os(CO)₃(thd). Upon treatment of 1 with Me₃NO at an elevated temperature, oxidation of the CO ligand occurred at the position trans to the unique CO₂ ligand on the Os(CO)₃(thd) fragment, giving the formation of a second CO₂ cluster [Os₄(-H)(-CO₂)(thd)(CO)₁₂(NCMe)] (3), which is stabilized by a weakly coordinated acetonitrile molecule.     

Characteristic Features of the Formation of Copper(I) π-Complexes with N-Allyl Derivatives of Piperazinium Sulfamate

The crystals of two copper(I) complexes and piperazinium sulfamate were synthesized by ac electrochemical technique from Cu(NH₂SO₃)₂· xH₂O and N,N-diallylpiperazine, N-allylpiperazine, or piperazine titrated by sulfamic acid in aqueous methanol to pH 4. The crystal structures of the complexes were determined (DARCh diffractometer, MoK radiation, /2 scan mode). The crystal data: [C₃H₅NH(CH₂)₄NHC₃H₅]_0.5[Cu(NH₂SO₃)₂] · H₂O (I), space group P1¯, a = 8.053(1) Å, b = 10.247(2) Å, c = 8.918(2) Å, = 113.03(1)°, = 107.14(2)°, = 95.15(1)°, Z = 2; [NH₂(CH₂)₄NH₂]_0.5NH₂SO₃ (II), space group P2₁/a, a = 8.468(7) Å, b = 5.92(1) Å, c = 10.890(9) Å, = 100.40(9)°, Z = 4; {[C₃H₅NH(CH₂)₄NHC₃H₅][NH₂(CH₂)₄NH₂]}_0.5[Cu(NH₂SO₃)₃] · H₂O (III), space group P1¯, a = 11.729(3) Å, b = 8.266(2) Å, c = 10.611(3) Å, = 82.13(2)°, = 65.73(2)°, = 74.86(2)°, Z = 2. Structure III is a hybrid of elements of structures I and II and contains the -coordinated Cu(I) atom surrounded by three -donor sulfamate nitrogen atoms, which was found for the first time.     

Komplexe des zweiwertigen Molybdäns,Derivate des Oktahalodimolybdat(II)-Ions, 4. Mitt.: Darstellungen und Kristallstrukturen von zwei neutralen Komplexen mit 4-Methylpyridin

Mo₂Cl₄ Pic ₄·CHCl₃ (A) (Pic=4-methylpyridine) and Mo₂Br₄ Pic ₄ (B) crystallize in the monoclinic space group.A inC2/c (No. 15) witha=15.175 (4),b=10.847 (2),c=19.946 (6) and =104.52 (2)°;D _o=1.71 (2),D _c =1.72 gcm^–3 forZ=4.B inP2_l/n (No. 14) witha=9.270 (3),b=16.614 (5),c=9.305 (3) and =91.96 (5)°;D _o=2.03 (3),D _c =2.05 gcm^–3 forZ=2.Two halogens and 4-methylpyridines of the MoX ₂ Pic ₂ group are in the trans position. Mo–Mo bond lengths are 2.153 96) forA and 2.150 92) forB. Both molecules are situated on the inversion center resulting in the eclipsed configuration of the ligands around the molybdenum pair. The structure ofB has been refined to the conventionalR factors of 0.08 and 0.098. Disorder on the part of 4-methylpyridines and chloroform molecules stopped the refinement ofA at the endR value of 0.175.Mean Mo–X and Mo–N bonding distances are 2.40 (2), 2.25 (5) forA and 2.53 (3), 2.25 (1) forB.

     

Zum Verhalten von Ketenen gegenüber P−N-Yliden Reaktionen mit phosphororganischen verbindungen, 39. Mitt.

1,3-Skeletal rearrangement of N-substituted ketimines via a possible intimate ion pair is discussed. (CH₃)₃SiCH=C=O (1) reacts with N-(aziridinyl)-triphenylphosphinimine (2) to give N-(1-aziridinyl)-2-trimethylsilylketen-1-imines (3). The compounds3 b, c are thermally labile and do not undergo 1,3-rearrangement but a retro-ene type reaction to yield (CH₃)₃SiCH₂CN and 2,3-diphenyl-2H-azirine (4). Diphenylketene (5) reacts with N-(N, N-dialkylamino)-triphenylphosphinimines (6) to yield -(N-disubstituted-amino)-nitriles (7). , -Dimethyl--(triphenylphosphinimino)-acetonitrile (9) reacts with (5) at room temperature to form , -dimethyl--(2, 2-diphenylketen-1-imino)-acetonitrile (10) which rearranges at 80° to dimethyl diphenylsuccinonitrile (11). The reaction of5 with 7-(triphenylphosphinimino)-7-azabicyclo[4.1.0]heptane (12) gives tetraphenylsuccinonitrile13 and 7-(7-azabicyclo[4.1.0]heptane)-, -diphenylacetonitrile (14). Finally the synthesis of N-acylketenimines (16) from (5) and acyltriphenylphosphinimines (15) is reported.

---

---

38. Mitt.:Chr. Ivancsics undE. Zbiral, Mh. Chem.106, 839 (1975).     

Structure elucidation of acetylation products of 2-acyl-1,3-indanediones by correlation of infrared spectral data

Summary 2-(1-Acetoxyalkylidene)- and 2-(1-acetoxybenzylidene)-1,3-indanediones (1a–1e) were proven to be the products of acetylation of 2-acyl-1,3-indanediones (2a–2e) by ketene using a detailed investigation and correlation analysis of infrared spectral data as well as¹H-NMR and¹³C-NMR spectra. Study by means of CNDO/2 and MMPI methods also demonstrates that the structure1 is more stable as the alternative one of 2-acyl-3-acetoxy-2-indene-1-ones (5). It was shown that the recently proposed general correlations v(C=O)_s vs. v(C=O)_as and v(C=O) vs. X⁺(R) as well as the mechanical anharmonicities of asymmetric C=O stretching vibration can be successfully used as a tool of structural diagnostics of cyclic 1,3-dicarbonyl compounds.

---

Strukturaufklärung von Acetylierungsprodukten von 2-Acyl-1,3-indandionen mittels Korrelation von Infrarot-Daten

Zusammenfassung 2-(1-Acetoxyalkyliden)- und 2-(1-Acetoxybenzyliden)-1,3-indandione (1a–1e) wurden mittels einer detaillierten infrarot-spektroskopischen Untersuchung (IR-Korrelation) und¹H-NMR und¹³C-NMR Spektroskopie als Acetylierungsprodukte von 2-Acyl-1,3-indandionen (2a–2e) mit Keten nachgewiesen. CNDO/2- und MMPI-Rechnungen zeigten auch, daß Struktur1 stabiler ist, als die der alternativen 2-Acyl-3-acetoxy-2-inden-1-one5. Es wird gezeigt, daß die kürzlich vorgeschlagenen allgemeinen Korrelationen v(C=O)_s gengen v(C=O)_as und v(C=O) gegen X ⁺(R) und auch die mechanischen Anharmonizitäten der asymmetrischen C=O Streckschwingung erfolgreich als Werkzeug zur Strukturaufklärung cyclischer 1,3-Dicarbonyl-Verbindungen eingesetzt werden können.

     

Untersuchungen der Hydroxylammonium-Fluorozirconate(IV)

Summary Hydroxylammonium fluorozirconates have been investigated. Two new microcristalline phases have been isolated from aqueous solutions: (NH₃OH)₂ZrF₆ (1) and (NH₃OH)₃ZrF₇ (2). The crystals were prepared by slow evaporation of the solution of NH₂OH, Zr, and HF. Different compositions of the crystals were achieved by varying the molar ratios of the components. They were characterized by thermal analysis, vibrational spectroscopy, and structure (single crystal x-ray methods). (NH₃OH)₂ZrF₆ (1) crystallizes triclinic, P (No.: 2),a=7.400(2),b=7.609(2),c=7.887(2) Å, =57.29(3)°, =62.16(3)°, =67.83(2)°. (NH₃OH)₃ZrF₇ (2) crystallizes triclinic, P (No.: 2),a=7.128(1),b=7.989(1),c=8.888(1) Å, =109.72(1)°, =91.01(1)°, =104.27(1)°.

     

Complexes of rhodium carbonylchloride and phosphorus(iii) cyanides in mediated electrochemical reduction of 2-carbomethoxy-2-methyl-1,1-dichlorocyclopropane

Electrochemical reduction of the complexes Rh(CO)ClL₂ [L = (EtO)₂PCN (1), Ph₂PCN (2)] and Rh₂(CO)₄L [L = P(CN)₃ (3), (4)] and their catalytic properties in electrochemical reduction of 2-carbomethoxy-2-methyl-1,1-dichloro-cyclopropane were studied. The catalytic electroreduction of a substrate at the reduction potentials of the central ion was developed for complexes2–4. This process is accelerated substantially for complexes2 and3 in the presence of anthracene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1970–1972, October, 1995.     

Benzimidazole-based receptor for Zn2+ recognition in a biological system: a chemosensor operated by retarding the excited state proton transfer

A new benzimidazole-based receptor was developed with potential functional groups for excited state proton transfer (ESPT) through keto–enol tautomerism. The enol form of the receptor selectively recognizes Zn²⁺, allowing it to be used as a ratiometric fluorescence sensor in DMSO/CH₃CN (1:9, v/v). The binding event triggers a blue-shifted band through the modulation of charge transfer transitions. The sensor is applicable for recognizing Zn²⁺ in the cytoplasm of Saccharomyces cerevisiae.     

Rapid and Selective Detection of Cyanide Anion by Enhanced Fluorescent Emission and Colorimetric Color Changes at Micromole Levels in Aqueous Medium

One main source of cyanide (CN⁻) exposure for mammals is through the plant consumption; thus, the sensitive and selective cyanide detection in plant tissue is a significant and urgent work. Here, a simple sensor N′‐(2,4‐dihydroxybenzylidene)naphtha[2,1‐b]furan‐2‐carbohydrazide ( Q1‐3 ) was designed and synthesized for selective and sensitive dual‐channel detection of cyanide in aqueous medium (DMSO/H₂O, 1:9, v/v). Acylhydrazone and phenolic hydroxyl groups on Q1‐3 are the recognition sites, and naphthofuran group is the signal report group. The intramolecular charge transfer between the benzene group and naphthofuran group was impeded because of the electron‐withdrawing groups (hydroxyl) on sensor Q1‐3 . Interestingly, the sensor Q1‐3 exhibited an intramolecular charge transfer absorption band at 400 nm and emission band at 500 nm, respectively, directly realizing an “OFF–ON” response after the deprotonation process induced by cyanide anions in aqueous medium (DMSO/H₂O, 1:9, v/v). Notably, this sensor was successfully applied to detect cyanide anions in food samples, which proves a very simple and selective platform for on‐site monitoring of cyanide in agriculture samples. In addition, the test strips and silica gel plates based on Q1‐3 were also fabricated, which could act as test kits and silica gel plates for convenient and efficient detection of cyanide anions.