Vibrational spectra of nitrido and oxo complexes

The vibrational spectra of a number of transition-metal complexes containing terminal or bridging nitrido (N^3?) and oxo (O^2?) ligands are reported. Full assignments of fundamental modes are given for (OsO₃¹⁴N)^?, (OsO₃¹⁵N)^?, (Os¹⁴NX₄)^?, (Os¹⁵NX₄)^?, (Ru¹⁴NX₄)^?, (Os¹⁴NX₅)^2?, (Os¹⁵NX₅)^2? and (Ru¹⁴NX₅)^2? (X = Cl, Br), and also for the oxo complexes (Mo¹⁶OCl₄, (Mo¹⁸OCl₄)^?, (Mo¹⁶OCl₅)^2? and (Mo¹⁸OCl₅)^2?. Force constants have been evaluated for the four- and five-coordinate complexes. The significance of the results is discussed in terms of the metalligand bonding involved in these species.     

The use of ferrocene in organometallic synthesis: A two-step preparation of cyclopentadienyliron acetonitrile and phosphine cations via photolysis of cyclopentadienyliron tricarbonyl or arene cations

UV photolysis of [CpFe^II(CO)₃]⁺ PF6₆^? (I) or [CpFe^II(η⁶-toluene)]⁺ PF₆^?? (II) in CH₃CN in the presence of 1 mole of a ligand L gives the new air sensitive, red complexes [CpFe^II(NCCH₃)₂L]⁺PF₆^? (III, L = PPh₃; IV; L = CO; VIII, L = cyclohexene; IX, L = dimethylthiophene) and the known air stable complex [CpFe^II(PMe₃)₂(NCMe)]⁺ PF₆^? (V). The last product is also obtained by photolysis in the presence of 2 or 3 moles of PMe₃. In the presence of dppe, the known complex [CpFe^II (dppe)(NCCH₃)]⁺ (XI) is obtained. Complex III reacts with CO under mild conditions to give the known complex [CpFe(NCCH₃)(PPh₃)CO]⁺ PF₆^? (X). UV photolysis of I in CH₃CN in the presence of 1-phenyl-3,4-dimethylphosphole (P) gives [CpFe^IIP₃]⁺ PF₆^? (XII); UV photolysis of II in CH₂Cl₂ in the presence of 3 moles of PMe₃ or I mole of tripod (CH₃C(CH₂Ph₂)₃) provides an easy synthesis of the known complexes [CpFe^II(PMe₃)₃]⁺ PF₆^? (VII) or [CpFe^IIη³-tripod]⁺ PF₆^t- (XIII). Since I and II are easily accessible from ferrocene, these photolytic syntheses provide access to a wide range of piano-stool cyclopentadienyliron(II) cations in a 2-step process from ferrocene.     

Thermal decomposition of butylindium thiolates and preparation of indium sulfide powders

Thermal properties of organoindium thiolates were investigated by means of thermogravimetric (TG) and differential thermal (DT) analysis. Dibutyl-indium propylthiolates (Buⁿ₂InSPrⁿ, Buⁿ₂InSPrⁱ, Buⁱ₂InSPrⁿ and Buⁱ₂InSPrⁱ) decomposed up to 280°C along with an exothermic DT peak and gave indium(I) sulfide (InS) powders. Although the arylthiolate Buⁿ₂InSPh also afforded InS powders, it decomposed at a slightly higher temperature. In contrast, the dithiolate and the dithiocarbamate complexes [BuⁿIn(SPrⁱ)₂ and In (S₂CNBu₂)₃] gave indium(III) sulfide (In₂S₃) powders.     

High-resolution UV photoelectron spectroscopy of diatomic halogens

Diatomic halogens are studied with UV photoelectron spectroscopy using new techniques to preserve high resolution even for reactive species. For the first time vibrational structure is observed on the ²Π_u,i (i = ^1/2,^3/2) states (F₂⁺, Cl₂⁺), the ²Σ_g⁺ states (F₂⁺, Cl₂⁺) and the Br₂⁺ (²Π_{u,$\text{3}\text{2}$}) state. On the ²Π_u,i states (F₂⁺, Cl₂⁺, Br₂⁺) spin-orbit splitting is resolved. Indications for a small potential barrier on the F₂⁺ (²Π_u,i) state for large internuclear distances are found. A new value for the spin-orbit splitting of the Cl₂⁺(²Π_g) state is presented (= ?725 cm^?1). The complementary nature of optical emission and photoelectron spectroscopy for small ions is demonstrated leading to a more complete picture of the F₂⁺ (²Π_u,i) and Cl₂⁺ (²Π_u,i) ionic states.     

Univalent Gallium Complexes of Simple and ansa‐Arene Ligands: Effects on the Polymerization of Isobutylene

Using [Ga(C₆H₅F)₂]⁺[Al(OR^F)₄]^?( 1 ) (R^F=C(CF₃)₃) as starting material, we isolated bis‐ and tris‐η⁶‐coordinated gallium(I) arene complex salts of p‐xylene (1,4‐Me₂C₆H₄), hexamethylbenzene (C₆Me₆), diphenylethane (PhC₂H₄Ph), and m‐terphenyl (1,3‐Ph₂C₆H₄): [Ga(1,4‐Me₂C₆H₄)_2.5]⁺ ( 2⁺ ), [Ga(C₆Me₆)₂]⁺ ( 3⁺ ), [Ga(PhC₂H₄Ph)]⁺ ( 4⁺ ) and [(C₆H₅F)Ga(μ‐1,3‐Ph₂C₆H₄)₂Ga(C₆H₅F)]²⁺ ( 5²⁺ ). 4⁺ is the first structurally characterized ansa‐like bent sandwich chelate of univalent gallium and 5²⁺ the first binuclear gallium(I) complex without a Ga?Ga bond. Beyond confirming the structural findings by multinuclear NMR spectroscopic investigations and density functional calculations (RI‐BP86/SV(P) level), [Ga(PhC₂H₄Ph)]⁺[Al(OR^F)₄]^?( 4 ) and [(C₆H₅F)Ga(μ‐1,3‐Ph₂C₆H₄)₂Ga(C₆H₅F)]²⁺{[Al(OR^F)₄] ^?}₂ ( 5 ), featuring ansa‐arene ligands, were tested as catalysts for the synthesis of highly reactive polyisobutylene (HR‐PIB). In comparison to the recently published 1 and the [Ga(1,3,5‐Me₃C₆H₃)₂]⁺[Al(OR^F)₄]^? salt ( 6 ) (1,3,5‐Me₃C₆H₃=mesitylene), 4 and 5 gave slightly reduced reactivities. This allowed for favorably increased polymerization temperatures of up to +15 °C, while yielding HR‐PIB with high contents of terminal olefinic double bonds (α‐contents=84–93 %), low molecular weights (M_n=1000–3000 g mol^?1) and good monomer conversions (up to 83 % in two hours). While the chelate complexes delivered more favorable results than 1 and 6 , the reaction kinetics resembled and thus concurred with the recently proposed coordinative polymerization mechanism.     

Effect of Partial Hydrolysis in Switching the Mode of Inter‐molecular Bonding between Metal Complexes

The assembly of [Cd(L¹)]^— {[L¹]^3— = N[CH₂CH₂N=C(CH₃)COO^—]₃} into the tetranuclear cluster {[Cd(L¹)]Na(H₂O)₂}₂ in the presence of Na⁺ is mediated by Na⁺‐carboxylate interactions; in contrast In³⁺ and Fe³⁺ induce the partial hydrolysis of [L¹]^3— to afford the complexes [In(L²)Cl] and {[Fe(L²)]₂O} {[L²]^2— = N[CH₂CH₂NH₂][CH₂CH₂N=C(CH₃)COO^—]₂} which aggregate via intermolecular H‐bonding.     

Formation and Reactivity of Organo‐Functionalized Tin Selenide Clusters

Reactions of R¹SnCl₃ (R¹=CMe₂CH₂C(O)Me) with (SiMe₃)₂Se yield a series of organo‐functionalized tin selenide clusters, [(SnR¹)₂SeCl₄] ( 1 ), [(SnR¹)₂Se₂Cl₂] ( 2 ), [(SnR¹)₃Se₄Cl] ( 3 ), and [(SnR¹)₄Se₆] ( 4 ), depending on the solvent and ratio of the reactants used. NMR experiments clearly suggest a stepwise formation of 1 through 4 by subsequent condensation steps with the concomitant release of Me₃SiCl. Furthermore, addition of hydrazines to the keto‐functionalized clusters leads to the formation of hydrazone derivatives, [(Sn₂(μ‐R³)(μ‐Se)Cl₄] ( 5 , R³=[CMe₂CH₂CMe(NH)]₂), [(SnR²)₃Se₄Cl] ( 6 , R²=CMe₂CH₂C(NNH₂)Me), [(SnR⁴)₃Se₄][SnCl₃] ( 7 , R⁴=CMe₂CH₂C(NNHPh)Me), [(SnR²)₄Se₆] ( 8 ), and [(SnR⁴)₄Se₆] ( 9 ). Upon treatment of 4 with [Cu(PPh₃)₃Cl] and excess (SiMe₃)₂Se, the cluster fragments to form [(R¹Sn)₂Se₂(CuPPh₃)₂Se₂] ( 10 ), the first discrete Sn/Se/Cu cluster compound reported in the literature. The derivatization reactions indicate fundamental differences between organotin sulfide and organotin selenide chemistry.     

Overlooked Formation of Carbonate Radical Anions in the Oxidation of Iron(II) by Oxygen in the Presence of Bicarbonate

Iron(II), (Fe(H₂O)₆²⁺, (Fe^II) participates in many reactions of natural and biological importance. It is critically important to understand the rates and the mechanism of Fe^II oxidation by dissolved molecular oxygen, O₂, under environmental conditions containing bicarbonate (HCO₃⁻), which exists up to millimolar concentrations. In the absence and presence of HCO₃⁻, the formation of reactive oxygen species (O₂⋅⁻, H₂O₂, and HO⋅) in Fe^II oxidation by O₂ has been suggested. In contrast, our study demonstrates for the first time the rapid generation of carbonate radical anions (CO₃⋅⁻) in the oxidation of Fe^II by O₂ in the presence of bicarbonate, HCO₃⁻. The rate of the formation of CO₃⋅⁻ may be expressed as d[CO₃⋅⁻]/dt=[Fe^II[[O₂][HCO₃⁻]². The formation of reactive species was investigated using ¹H nuclear magnetic resonance (¹H NMR) and gas chromatographic techniques. The study presented herein provides new insights into the reaction mechanism of Fe^II oxidation by O₂ in the presence of bicarbonate and highlights the importance of considering the formation of CO₃⋅⁻ in the geochemical cycling of iron and carbon.     

Synthesis of novel termetallic isopropoxides

Novel termetallic isopropoxides are reported which may be represented by the general formulae: [(PrⁱO)₃M(μ-OPrⁱ)₂Be(μ-OPrⁱ)₂Al(OPrⁱ)₂], [(PrⁱO)₂M(μ-OPrⁱ)₂Be(μ-OPrⁱ)₂Al(OPrⁱ)₂]₂ [where M = Ti(IV), Zr(IV) and Hf(IV)] and [(PrⁱO)₄M(μ-OPrⁱ)₂Be(μ-OPrⁱ)₂Al(OPrⁱ)₂] [where M = Nb(V) and Ta(V)]. Attempts to synthesize derivatives with the general formula, [(PrⁱO)₇M₂(μ-OPrⁱ)₂Be(μ-OPrⁱ)₂Al(OPrⁱ)₂] [where M = Ti(IV), Zr(IV) or Hf(IV)], were unsuccessful and in all such cases a mixture of M(OPrⁱ)₄ and [(PrⁱO)₃M(μ-OPrⁱ)₂Be(μ-OPrⁱ)₂Al(OPrⁱ)₂] was obtained. All these derivatives are soluble in common organic solvents and with the exception of titanium(IV) derivatives, they can be volatilised without noticeable disproportionation. These products have been characterized by elemental analyses, molecular weights, IR, ¹H NMR and (in representative cases) mass spectral studies also.     

A flowing afterglow study of uranium tetraborohydride

Ionization-fragmentation of uranium(IV) tetraborohydride, U(BH₄)₄, by He⁺ and by N⁺/N₂⁺ yields, predominantly, U(BH₅)⁺ and U(B₂H₈)⁺, respectively. Attachment of thermal electrons yields U(BH₄)₄^? and ions of 1, 2, and 3 mass units less. Fluoride transfer with SF₆^?, BF₄^?, and UF_n^? (n = 5–7) and reactions with other small ions (O^?, O₂^?, NO₂^?, F^?, Cl^?, O₂⁺) are described.     

Homo- and hetero-dinuclear derivatives of aluminium containing Schiff-base ligands: synthesis,characterization and antibacterial activity of mononuclear derivative of aluminium

Reactions of Al(OPrⁱ)₃ with LH₂ =?[R′C(NYOH)CHC(R)OH] R=R′=CH₃, Y =?(CH₂)₂ (L¹H₂); R =?CH₃, R′ =?C₆H₅, Y =?(CH₂)₂ (L²H₂); R =?R′ =?CH₃, Y =?(CH₂)₃ (L³H₂); R =?CH₃, R′ =?C₆H₅, Y =?(CH₂)₃ (L⁴H₂), in 1 : 2 molar ratio give mononuclear derivatives of aluminium AlLLH (1a–1d). Equimolar reactions of AlLLH with M(OPrⁱ)₃ (M =?Al and B) yield homo- and hetero-dinuclear derivatives AlLLM(OPrⁱ)₂ (M=Al=2a–2d M=B=3a–3d). Reaction of 2a with L¹H₂ affords AlL¹L¹AlL¹ (4). All these derivatives have been characterized by elemental analysis, molecular weight measurements and plausible structures have been suggested on the basis of IR, NMR [¹H, ¹³C, ²⁷Al and ¹¹B] spectral data and FAB-mass studies of 2b and 3b. Schiff base L¹H₂ and its mononuclear derivative with aluminium (AlL¹L¹H) have been screened for their antibacterial activity against Escherischia coli and Bacillus subtilis.     

Modeling of the molecular and electronic structures of some mono- and biosmium complexes of fullerene C60

The modeling of the molecular and electronic structures of the following mono- and biosmium complexes of fullerene C₆₀ was performed by quantum chemical methods (MNDO/PM3 and DFT/PBE): (??²-C₆₀)[Os(PPh₃)₂(CO)CNMe], (??²,??²-C₆₀)[Os(PPh₃)₂(CO)(CNMe)]₂, (??²-C₆₀)[Os(PH₃)₂(CO)H], (??²,??²-C₆₀)[Os(PH₃)₂(CO)H]₂, (??²-C₆₀)[Os(PH₃)₂(CO)CNMe], (??²,??²-C₆₀)[Os(PH₃)₂(CO)CNMe]₂, and (5-C₆₀H₅)[Os(C₅H₅)], (5, 5-C₆₀H₁₀)[Os(C₅H₅)]₂.The osmium atoms in the first six complexes are ??²-coordinated by fullerene C₆₀. In the last two complexes, the ??⁵-coordination mode is observed. The structures of the radical anions of these complexes were calculated. The energies of the frontier orbitals were evaluated. The acceptor properties of the complexes are discussed. The electron affinities were estimated in two ways: from the energy of the lowest unoccupied molecular orbital (LUMO) and as the energy difference between the neutral molecule and its radical anion.     

The study of distribution coefficients of silver and mercury with chelating ion-exhange resin Dowex A-1

The distribution coefficients (DC) for HgCl ₄ ^2– , Hg(SO₄) ₂ ^2– , Hg(NO₃) ₄ ^2– , Ag⁺, Ag(SCN) ₂ ^– and Ag(NH₃) ₂ ⁺ between aqueous solutions and Dowex A-1 were measured in varying hydrogen ion concentrations. The DC of Ag⁺ in the NO ₃ ^– media was very low (4 to 6). The DC for the Ag(SCN) ₂ ^– complex decreased as pH increased. The Ag(NH₃) ₂ ⁺ complex had a constant DC of about 65 from pH 8 and above. The trend observed for three mercury complexes in HCl, H₂SO₄ and HNO₃ was similar; the DC decreased steadily from 0.1M to 6M. The HgCl ₄ ^2– complex had the highest DC (9000) while the Hg(NO₃) ₄ ^2– complex had the lowest DC (2000).     

Pulsed,Crossed, Supersonic Molecular Beam Studies of Refractory Atom Reactions

Dynamics of refractory atom reactions have been studied with a crossed beam apparatus combining two pulsed, supersonic molecular beam sources, a pulsed UV laser for creating the refractory atoms in the gas phase by laser ablation, and a pulsed dye laser to probe the reaction products by laser-induced fluorescence. Examples of the A1(²P_j) + O₂(X³∑_g)→ A10(X²∑⁺) + O(³P_j), Mg(¹S_o) + N₂O(X¹∑⁺) → MgO(X¹∑⁺,a³Π) + N₂(X¹∑_g⁺) andC(³P_j) + NO(X²Π_r) → CN(X²∑⁺) + 0(³P_j) systems are given. Comparisons with the studies performed using the conventional steady-state beam approach are made.     

Spin-adducts of radicals ·P(O)(OPri)2 and ·CMe3 with pyrrolidino[60]fullerenes studied by ESR spectroscopy

The addition of the ^·Bu^t (R¹) and ^·P(O)(OPrⁱ)₂ (R²) radicals to pyrrolidino[60]fullerenes C₆₀CH₂NMeCHX (X = C₆H₄N(CH₂CH₂Cl)₂, 2,6-(Bu^t)₂C₆H₂OH, PhC₆H₄, and indol-3-yl) was studied by ESR spectroscopy. The rate constants of R¹ radical addition to these compounds and dimerization of spin-adducts of the R¹ radicals with pyrrolidino[60]fullerenes were determined. Pyrrolidino[60]fullerenes manifest considerably higher reactivity toward the R¹ radicals than fullerene C₆₀ and methanofullerenes C₆₀CX¹X² (X¹ = X² = CO₂Et; X¹ = CO₂Me, X² = OP(OMe)₂, X¹ = X² = OP(OEt)₂).     

Luminescence Tuning of Upconversion Nanocrystals

Upconversion luminescence tuning of β‐NaYF₄ nanorods under 980 nm excitation has successfully been achieved by tridoping with Ln³⁺ ions with different electronic structures. The effects of Ce³⁺ ions on NaYF₄:Yb³⁺/Ho³⁺ as well as Gd³⁺ ions on NaYF₄:Yb³⁺/Tm³⁺(Er³⁺) have been studied in detail. By tridoping with Ce³⁺ ions, not only were unusual ⁵G₅→⁵I₇ and ⁵F₂/³K₈→⁵I₈ transitions from Ho³⁺ ions and 5d→4f transitions from Ce³⁺ ions observed in NaYF₄:Yb³⁺/Ho³⁺ nanorods, but also an increase in the intensity of ⁵F₅→⁵I₈ relative to ⁵S₂/⁵F₄→⁵I₈ with increasing Ce³⁺ concentration, which can be attributed to efficient energy transfers of ⁵I₆ (Ho)+²F_5/2 (Ce)→⁵I₇ (Ho)+²F_7/2 (Ce) and ⁵S₂/⁵F₄ (Ho)+²F_5/2 (Ce)→⁵F₅ (Ho)+²F_7/2 (Ce). Interestingly, with increasing pump power density, the luminescence of NaYF₄:Yb³⁺/Ho³⁺ nanorods is always dominated by the ⁵S₂/⁵F₄→⁵I₈ transition, whereas the luminescence of Ce³⁺‐tridoped NaYF₄:Yb³⁺/Ho³⁺ nanorods is dominated by the ⁵S₂/⁵F₄→⁵I₈ and ⁵G₅→⁵I₇ transitions in turn. These observations are discussed on the basis of a rate equation model. Furthermore, Gd³⁺‐tridoped NaYF₄:Yb³⁺/Tm³⁺(Er³⁺) nanorods can emit multicolor upconversion emissions spanning from the UV to the near‐infrared under 980 nm excitation. ⁶P_5/2→⁸S_7/2 (≈306 nm) and ⁶P_7/2→⁸S_7/2 (≈311 nm) transitions from Gd³⁺ ions were observed. In addition to the aforementioned luminescence properties, these Gd³⁺‐tridoped nanorods also exhibit paramagnetic behavior at room temperature and superparamagnetic behavior at 2 or 5 K.     

Formation,Expansion, and Interconversion of Metallarings in a Sulfur‐Bridged AuICoIII Coordination System

A novel Au^ICo^III coordination system that is derived from the newly prepared [Co(D ‐nmp)₂]⁻ ( 1 ⁻; D ‐nmp=N‐methyl‐D ‐penicillaminate) and a gold(I) precursor Au^I is reported. Complex 1 ⁻ acts as a sulfur‐donating metallaligand and reacts with the gold(I) precursor to give [Au₂Co₂(D ‐nmp)₄] ( 2 ), which has an eight‐membered Au^I₂Co^III₂ metallaring. Treatment of 2 with [Au₂(dppe)₂]²⁺ (dppe=1,2‐bis(diphenylphosphino)ethane) leads to the formation of [Au₄Co₂(dppe)₂(D ‐nmp)₄]²⁺ ( 3 ²⁺), which consists of an 18‐membered Au^I₄Co^III₂ metallaring that accommodates a tetrahedral anion (BF₄⁻, ClO₄⁻, ReO₄⁻). In solution, the metallaring structure of 3 ²⁺ is readily interconvertible with the nine‐membered Au^I₂Co^III metallaring structure of [Au₂Co(dppe)(D ‐nmp)₂]⁺ ( 4 ⁺); this process depends on external factors, such as solvent, concentration, and nature of the counteranion. These results reveal the lability of the Au S and Au P bonds, which is essential for metallaring expansion and contraction.     

Halide and complex halogeno anions as salts of oxinate chelates of titanium(IV)

(η⁵-Cyclopentadienyl)(η⁵-pyrrolyl)titanium(IV) dichloride, (η⁵-indenyl)-(η⁵-pyrrolyl)titanium(IV) dichloride and (η⁵-cyclopentadienyl)(η⁵-indenyl)-titanium(IV) dichloride, when treated with 8-hydroxyquinoline (oxine) in aqueous medium form ionic derivatives of the type, [(η⁵-R)(η⁵-R′)TiL]⁺ Cl^- (R = C₅H₅, C₉H₇, R′ = C₄H₄N; R = C₅H₅, R′ = C₉H₇; L is the conjugate base of (oxine). A number of halide and complex halogeno anions present in aqueous solution were isolated as salts of these ionic complexes giving derivatives of the type, [(η⁵-R)(η⁵-R′)TiL]⁺ X^- (X = Br^-, I^-, ZnCl₃(H₂O)^-, CdCl₄^2-, HgCl₃^-). Conductivity measurements in nitrobenzene solution indicate that these complexes are electrolytes. Both the IR and ¹H NMR spectral studies demonstrate that the ligand L is chelating. Consequently there is tetrahedral coordination about the titanium(IV) ion.     

Cationic iridium complexes of the Xantphos ligand. Flexible coordination modes and the isolation of the hydride insertion product with an alkene

Reaction of the Ir(I)-Xantphos complex [Ir(κ²-Xantphos)(COD)][BAr^F₄] (Xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, Ar^F = C₆H₃(CF₃)₂) with H₂ in acetone or CH₂Cl₂/MeCN affords the Ir(III)-hydrido complexes [Ir(κ³-Xantphos)(H)₂(L)][BAr^F₄], L = acetone or MeCN, whereas in non-coordinating CH₂Cl₂ solvent dimeric [Ir(κ³-Xantphos)(H)(μ-H)]₂[BAr^F₄]₂ is formed. A common intermediate in these reactions that invokes a (σ, η²-C₈H₁₃) ligand is reported. Addition of excess tert-butylethene (tbe) to [Ir(κ³-Xantphos)(H)₂(MeCN)][BAr^F₄] results in insertion of a hydride into the alkene to form [Ir(κ³-Xantphos)(MeCN)(CH₂CH₂C(CH₃)₃)(H)][BAr^F₄], an Ir(III) alkyl-hydrido-Xantphos complex. This reaction is reversible, and heating (80 °C) results in the reformation of [Ir(κ³-Xantphos)(H)₂(MeCN)][BAr^F₄] and tbe. These complexes have been characterised by NMR spectroscopy, ESI-MS and single-crystal X-ray diffraction. They show variable coordination modes of the Xantphos ligand: cis-κ²-P,P, fac-κ³-P,O,P and mer-κ³-P,O,P with the later coordination mode like that found in related PNP-pincer complexes.     

Kinetics and Mechanism of the Cerium(IV) Oxidation of Arnold's Base and the Protonation and Hydroxylation of Michler's Hydrol Blue

In aqueous H₂SO₄, Ce(IV) ion oxidizes rapidly Arnold's base((p-Me₂NC₆H₄)₂CH₂, Ar₂CH₂) to the protonated species of Michler's hydrol((p-Me₂NC₆H₄)₂CHOH, Ar₂CHOH) and Michler's hydrol blue((p-Me₂NC₆H₄)₂CH⁺, Ar₂CH⁺). With Ar₂CH₂ in excess, the rate law of the Ce(IV)-Ar₂CH₂ reaction in 0.100 M H₂SO₄ is expressed -d[Ce(IV)]/dt = k_app[Ar₂CH₂]₀[Ce(IV)] with k_app = 199 ± 8M^?1s^?1 at25°C. When the consumption of Ce(IV) ion is nearly complete, the characteristic blue color of Ar₂CH⁺ ion starts to appear; later it fades relatively slowly. The electron transfer of this reaction takes place on the nitrogen atom rather than on the methylene carbon atom. The dissociation of the binuclear complex [Ce(III)ArCHAr-Ce(III)] is responsible for the appearance of the Ar₂CH⁺ dye whereas the protonation reaction causes the dye to fade. In highly acidic solution, the rate law of the protonation reaction of Michler's hydrol blue is -d[Ar₂CH⁺]/dt = k_obs[Ar₂CH⁺] where K_obs = ((ac + 1)[H*] + bc[H⁺]²)/(a + b[H⁺]) (in HClO₄) and k_obs= ((ac + 1 + e[HSO₄^?])[H⁺] + bc[H⁺]² + d[HSO₄^?] + q[HSO₄^?]²/[H⁺])/(a + b[H⁺] + f[HSO₄^?] + g[HSO₄^?]/[H⁺]) (in H₂SO₄), and at 25°C and μ = 0.1 M, a = 0.0870 M s, b = 0.655 s, c = 0.202 M^?1s^?1, d = 0.110, e = 0.0070 M^?1, f = 0.156 s, g = 0.156 s, and q = 0.124. In highly basic solution, the rate law of the hydroxylation reaction of Michler's hydrol blue is -d[Ar₂CH⁺]/dt = k_OH[OH^?]₀[Ar₂CH⁺] with k_OH = 174 ± 1 M^?1s^?1 at 25°C and μ = 0.1 M. The protonation reaction of Michler's hydrol blue takes place predominantly via hydrolysis whereas its hydroxylation occurs predominantly via the path of direct OH attack.