Cracking down on vapochromic salts: unveiling vapomechanical stress in gas-sorbing platinum complexes.

This study explores the vapochromic and vapoluminescent behaviors of [Pt(tpy)Cl]PF host molecules (tpy = 2,2':6',2''-terpyridine) under acetonitrile (CHCN) vapor guest, challenging the conventional view that these phenomena arise solely from direct host-guest interactions. Our findings reveal a cooperative mechanism where mechanochromic surface perturbations prime the Pt(II) host for guest incorporation, leading to initial color and luminescence changes prior to significant structural alterations. While the color transition between the yellow [Pt(tpy)Cl]PF form and the red/orange [Pt(tpy)Cl]PF·CHCN form is reversible, repeated vapor cycling induces a loss of crystallinity, as indicated by diffraction peak broadening and emission shifts.

Optical sensing of aqueous nitrate anion by a platinum(II) triimine salt based solid state material.

Selective and quantitative measurement of aqueous nitrate (NO) anion is achieved using solid [Pt(Cl-4-tpy)Cl]ClO salt (Cl-4-tpy = 4-chloro-2,2':6'2''-terpyridine), and as the salt supported on controlled porous glass. This detection method relies on the color change of the Pt(II) complex from yellow to red and intense luminescence response upon ClO exchange with NO due to concomitant enhancement of Pt⋯Pt interactions. The spectroscopic response is highly selective for NO over a large range of halides and oxoanions.

Water's Role in Polymorphic Platinum(II) Complexes.

Solvent plays a vital role in the recrystallization process and resulting crystallinity of materials. This role is of such importance that it can control the stability and utility of materials. In this work, the inclusion of a solvent in the crystalline lattice, specifically water, drastically affects the overall stability of two platinum polymorphs.

pH-Mediated Colorimetric and Luminescent Sensing of Aqueous Nitrate Anions by a Platinum(II) Luminophore@Mesoporous Silica Composite.

Increased levels of nitrate (NO) in the environment can be detrimental to human health. Herein, we report a robust, cost-effective, and scalable, hybrid material-based colorimetric/luminescent sensor technology for rapid, selective, sensitive, and interference-free NO detection. These hybrid materials are based on a square-planar platinum(II) salt [Pt(tpy)Cl]PF (tpy = 2,2';6',2″-terpyridine) supported on mesoporous silica.

Phase transformation induced mechanochromism in a platinum salt: a tale of two polymorphs.

Red crystals of [Pt(tpy)Cl]NO3·HNO3 show mechanochromic behaviour turning yellow when pressure is applied. The electronic character and spectroscopic signature of the red and yellow polymorphs change as a result of slipping of the molecular stacking planes in the solid state. The slippage alters the PtPt intermolecular distances from a linear stacked motif with <3.

Solution aggregation of platinum(ii) triimine methyl complexes.

The NMR chemical shifts of [Pt(tpy)(CH3)](PF6) (1) and [Pt(mbzimpy)(CH3)](PF6) (2), where tpy = 2,2';6'2''-terpyridine and mbzimpy = 2,6-bis(N-methylbenzimidazol-2-yl)pyridine, in room-temperature DMSO-d6 displayed concentration dependence as a result of formation of dimers. Quantification of these dimers, expressed by equilibrium constant (K), shows a greater tendency of 2 to aggregate in solution. Structural conformations of these dimers were confirmed by 2D 1H-1H NOESY; the results explicitly suggest a head-to-tail stacking arrangement of molecules in dimers.

Luminescent Pt(2,6-bis(N-methylbenzimidazol-2-yl)pyridine)X: a comparison with the spectroscopic and electrochemical properties of Pt(tpy)X (X = Cl, CCPh, Ph, or CH).

A series of platinum(ii) pincer complexes of the formula Pt(mbzimpy)X+, 1(a-d), (mbzimpy = 2,6-bis(N-methylbenzimidazol-2-yl)pyridine; X = Cl; (a), CCPh; (b), Ph; (c), or CH3; (d), CCPh = phenylacetylide, and Ph = Phenyl) have been synthesized and characterized. Electronic absorption and emission, as well as electrochemical properties of these compounds, have been investigated. Pt(tpy)X+ analogs (tpy = 2,2';6'2''-terpyridine), 2(a-d), have also been investigated and compared.

A digital imaging method for evaluating the kinetics of vapochromic response.

This work describes the novel use of a cell phone camera and the L*a*b method (color space defined by the International Commission on Illumination) to characterize the color change in different vapochromic platinum(II) complexes in order to get quantitative and more reliable data. In this study, we have developed a semi-automatic CCA software that digitally analyzes images (e.g.

Spectroscopic Characterization of Platinum(IV) Terpyridyl Complexes.

Pt(tpy)X [X = Cl (), Br (); tpy = 2,2':6',2″-terpyridine] salts were prepared by the oxidative addition of Pt(tpy)X with X as originally reported by Morgan and Burstall in 1934. The complexes have been fully characterized by H NMR spectroscopy, elemental analysis, mass spectrometry, and X-ray crystallography. The electronic structures of and were investigated using absorption and emission spectroscopy, and the accumulated data are consistent with stabilization of the singlet ligand-centered and potentially singlet ligand field/singlet ligand-to-metal charge-transfer states for and compared to those for Pt(tpy)Cl () and Pt(tpy)Br ().

Halide exchange studies of novel Pd(ii) NNN-pincer complexes.

Palladium(ii) complexes with an NNN type pincer ligand (pipNNN = 2,6-bis(piperdyl-methyl)pyridine) are synthesized and characterized. Electronic and H NMR spectra point to decreasing filled/filled repulsions between the dπ(Pd) orbitals and the halide lone pair orbitals along the Cl < Br < I series. For all complexes, the most downfield α-piperidyl resonance of the pipNNN ligand is sensitive to changes in the coordinated halide while the -pyridyl and benzylic resonances are sensitive to changes in the counter anion.

Synthesis, Luminescence, and Structure of a Polymorphic Polyfluorinated Diiodoplatinum(II) Diimine Complex.

PtI(5,5'-bis(HCFCHOCH)-2,2'-bpy)], , is the first example of a substituted fluorinated diiodoplatinum diimine complex that exhibits polymorphism. The complex, upon recrystallization, forms two different polymorphs, denoted as α and β forms. The luminescence of the α and β forms are the same in glassy solution at 77 K; however, in the solid state, they differ significantly.

Tuning two-electron transfer in terpyridine-based platinum(ii) pincer complexes.

An important factor in obtaining reversible multi-electron transfer is overcoming large changes in coordination geometry. One strategy is to use ligands that can support the geometries favored before and after the electron transfer. PipNCN pincer and terpyridine ligands are used to support square planar Pt(ii) and octahedral Pt(iv).

Assessing flammable storage cabinets as sources of VOC exposure in laboratories using real-time direct reading wireless detectors.

Herein we present the results of measurements using wireless direct-reading photoionization detector-based gas sensors to quantify concentrations of vapors of volatile organic compounds (VOCs) in and around flammable storage cabinets containing common organic solvents, including acetone, dichloromethane, trichloroethylene, and benzene. Such cabinets are commonly employed in laboratories to contain flammable liquids. A sensor array was deployed in a series of flammable storage cabinets in working laboratories.

Radio-Fluorogenic Gel Dosimetry with Coumarin.

Gel dosimeters are attractive detectors for radiation therapy, with properties similar to biological tissue and the potential to visualize volumetric dose distributions. Radio-fluorogenesis is the yield of fluorescent chemical products in response to energy deposition from ionizing radiation. This report shares the development of a novel radio-fluorogenic gel (RFG) dosimeter, gelatin infused with coumarin-3-carboxlyic acid (C3CA), for the quantification of imparted energy.

Analyte-responsive gated hollow mesoporous silica nanoparticles exhibiting inverse functionality and an AND logic response.

A multifunctional nanoparticle with designed selectivity was made using hollow mesoporous silica, ship-in-a-bottle synthesis of a crystalline solid-state detector, and protection of the crystal by acid-responsive nanogates. The system demonstrates the inverse application of the usual trapping of contents by the gate followed by their release. Instead, the gate protects the contents followed by selective exposure.

Highly Selective Colorimetric and Luminescence Response of a Square-Planar Platinum(II) Terpyridyl Complex to Aqueous TcO4(-).

Molecular recognition of an aqueous pertechnetate (TcO4(-)) anion is fundamentally challenging partly due to the charge-diffuse nature of this anion, which hampers design of new technologies for its separation and detection. To address this gap, simple salts of transition metal complexes that undergo a distinct spectroscopic change upon exposure to aqueous anions were explored. The Pt(II) complex [Pt(tpy)Br]SbF6 (tpy = 2,2';6',2″-terpyridine) undergoes a dramatic color change and intense luminescence response upon TcO4(-) uptake due to concomitant enhancement of Pt···Pt interactions.

Platinum(II) Monomer and Dimer Complexes with a Bis(oxazolinyl)phenyl Pincer Ligand.

A series of platinum(II) complexes with the formulas Pt(phebox)(L)(+) (phebox(-) = 1,3-bis(4,4'-dimethyl-2'-oxazolinyl)phenyl anion; L = pyridine (py), 4-phenylpyridine, quinoline, acridine) and Pt2(phebox)2(μ-L')(2+) (L' = pyrazine, 4,4'-bipyridine, 1,2-bis(4-pyridyl)ethane) was prepared. Crystallographic data establish that the metal center is bonded to the tridentate phebox(-) and monodentate pyridyl ligands. The five-membered oxazoline rings favor a CH2-CMe2 twist conformation.

In-house and synchrotron X-ray diffraction studies of 2-phenyl-1,10-phenanthroline, protonated salts, complexes with gold(III) and copper(II), and an orthometallation product with palladium(II).

Different salts of the 2-phenyl-1,10-phenanthrolin-1-ium cation, (pnpH)(+), are obtained by reacting 2-phenyl-1,10-phenanthroline (pnp), C18H12N2, (I), with a variety of anions, such as hexafluoridophosphate, C18H13N2(+)·PF6(-), (II), trifluoromethanesulfonate, C18H13N2(+)·CF3SO3(-), (III), tetrachloridoaurate, (C18H13N2)[AuCl4], (IV), and bromide (as the dihydrate), C18H13N2(+)·Br(-)·2H2O, (V). Compound (I) crystallizes with Z' = 2, with both independent molecules adopting a coplanar conformation. In (II)-(IV), a hydrogen bond exists between the cation and anion, while one of the lattice water molecules serves as a hydrogen-bonded bridge between the cation and anion in (V).

Ruthenium bis-diimine complexes with a chelating thioether ligand: delineating 1,10-phenanthrolinyl and 2,2'-bipyridyl ligand substituent effects.

Despite the high π-acidity of thioether donors, ruthenium(II) complexes with a bidentate 1,2-bis(phenylthio)ethane (dpte) ligand and two chelating diimine ligands (i.e., Ru(diimine)2(dpte)(2+)) exhibit room-temperature fluid solution emission originating from a lowest MLCT excited state (diimine = 2,2'-bipyridine, 5,5'-dimethyl-2,2'-bipyridine 4,4'-di-tert-butyl-2,2'-bipyridine, 1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 5-chloro-1,10-phenanthroline, 5-bromo-1,10-phenanthroline, 5-nitro-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, and 3,4,7,8-tetramethyl-1,10-phenanthroline).

Between red and yellow: evidence of intermediates in a vapochromic Pt(II) salt.

[Pt(tpy)Cl]ClO4·H2O (1·H2O) changes from red to yellow upon dehydration due to increased Pt···Pt distances. Spectroscopic, diffraction, gravimetric and calorimetric data demonstrate the presence of intermediates during hydration and dehydration which signifies surprising mechanistic complexity in the vapochromic response.

X-ray and synchrotron diffraction studies of 2-(pyridin-2-yl)-1,10-phenanthroline in the role of ligand for two copper polymorphs or hydrogen bonded with 2,2,6,6-tetramethyl-4-oxopiperidinium hexafluorophosphate.

Different extended packing motifs of dichlorido[2-(pyridin-2-yl)-1,10-phenanthroline]copper(II), [CuCl2(C17H11N3)], are obtained, depending on the crystallization conditions. A triclinic form, (I), is obtained from dimethylformamide-diethyl ether or methanol, whereas crystallization from dimethylformamide-water yields a monoclinic form, (II). In each case, the Cu(II) centre is in a five-coordinate distorted square-pyramidal geometry.

Platinum(II) diimine complexes with halide/pseudohalide ligands and dangling trialkylamine or ammonium groups.

A series of platinum(II) complexes with the formulas Pt(diimine)(pip(2)NCNH(2))(L)(2+) [pip(2)NCNH(2)(+) = 2,6-bis(piperidiniummethyl)phenyl cation; L = Cl, Br, I, NCS, OCN, and NO(2); diimine = 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO(2)phen), and 5,5'-ditrifluoromethyl-2,2'-bipyridine (dtfmbpy)] were prepared by the treatment of Pt(pip(2)NCN)Cl with a silver(I) salt followed by the addition of the diimine and halide/pseudohalide under acidic conditions. Crystallographic data as well as (1)H NMR spectra establish that the metal center is bonded to a bidentate phenanthroline and a monodentate halide/pseudohalide. The pip(2)NCNH(2)(+) ligand with protonated piperidyl groups is monodentate and bonded to the platinum through the phenyl ring.

Luminescence rigidochromism and redox chemistry of pyrazolate-bridged binuclear platinum(II) diimine complex intercalated into zirconium phosphate layers.

The direct intercalation of a pyrazolate-bridged platinum(II) bipyridyl dimer ([{Pt(dmbpy)(μ-pz)}(2)](2+); dmbpy = 4,4'-dimethyl-2,2'-bipyridine, pz(-) = pyrazolate) within a zirconium phosphate (ZrP) framework has been accomplished. The physical and spectroscopic properties of [{Pt(dmbpy)(μ-pz)}(2)](2+) intercalated in ZrP were investigated by X-ray powder diffraction and X-ray photoelectron, infrared, absorption, and luminescence spectroscopies. Zirconium phosphate layers have a special microenvironment that is capable of supporting a variety of platinum oxidation states.

Intramolecular NH···Pt interactions of platinum(II) diimine complexes with phenyl ligands.

Pt(pipNC)(2)(phen) [pipNC(-) = 1-(piperidylmethyl)phenyl anion; phen = 1,10-phenanthroline] was prepared by the reaction of cis-Pt(pipNC)(2) with phen. Crystallographic and (1)H NMR data establish that the phen ligand is bidentate, whereas each piperidyl ligand is monodentate and bonded to the platinum at the ortho position of the phenyl group. Acidic conditions allowed for isolation of the salts of diprotonated Pt(pipNHC)(2)(diimine)(2+) adducts (diimine = phen, 2,2'-bipyridine, or 5,5'-ditrifluoromethyl-2,2'-bipyridine).

Interaction of SbCl5(2-) and thioether groups at the open coordination sites of platinum(II) diimine complexes.

In the solid-state, the approximately square planar cation in orange crystals of [Pt(NO(2)phen)(ttcn)](PF(6))(2) (NO(2)phen = 5-nitro-1,10-phenanthroline; ttcn = 1,4,7-trithiacyclononane) has a short apical Pt...