Characterization and electrochemical studies of molybdenum(VI) dioxodialkylbipyridyl complexes. X-ray crystal structure of MoO2(o-MeC6H4CH2)2(bipy)

Summary New Mo^VI-dioxodialkyl complexes, MoO₂R₂(bipy), R = CH₂CH₂Ph and p-MeC₆H₄CH₂; bipy = 2,2-bipyridine, have been synthesized. The i.r. and the ¹H-n.m.r. spectra of these complexes are noted. The structure of MoO₂(o-MeC₆H₄CH₂)₂(bipy) was determined by X-ray analysis. Significant differences in the redox characteristics of these dioxodialkylcompounds are reflected in the contrasting patterns: whereas reduction of MoO₂-(CH₂CH₂Ph) ₂(bipy) is a reversible one-electron process, under similar conditions MoO₂(p-MeC₆H₄CH₂)₂(bipy) and MoO₂(o-MeC₆H₄CH₂)₂(bipy) are reduced irreversibly. Similarly, solutions of MoO₂(CH₂CH₂Ph)₂(bipy) remain unchanged but oxygenated organic products are formed from MoO₂(p-MeC₆H₄CH₂)₂(bipy) and MoO₂ (o-MeC₆H₄CH₂)₂(bipy).     

The steric effect of o-tolyl ligand on the fluxionality behavior of some binuclear organoplatinum(II) complexes with bis(diphenylphosphino)methane as bridging ligand

A series of binuclear organoplatinum(II) complexes of general formula cis,cis-[R₂Pt(μ-SMe₂)(μ-dppm)Pt(o-MeC₆H₄)₂], 3a-3d, in which R = Ph, p-MeC₆H₄, m-MeC₆H₄ or p-MeOC₆H₄, were prepared by the reaction of monomeric precursors [Pt(o-MeC₆H₄)₂(dppm)] and cis-[PtR₂(SMe₂)₂]. The binuclear dialkyl analogs, in which R = Me (3e) or R₂ = {(CH₂)₄} (3f), were prepared by the reaction of cis-[Pt(o-MeC₆H₄)₂ (SMe₂)₂] and [PtR₂ (dppm)]. The complexes were fully characterized by multinuclear (¹H, ¹³C, ³¹P, ¹⁹⁵Pt) NMR spectroscopy each as a mixture of syn and anti isomers (depending on the relative orientations of Me substituents on o-tolyl ligands) and each isomer was shown to have a rigid structure. Other binuclear analogs , 3g-3j, in which R is a less steric demanding aryl groups m-MeC₆H₄ or p-MeOC₆H₄, and R′ = Me or , were prepared by the reaction of cis-[PtR₂(SMe₂)₂] and , and shown to have fluxional structures.     

Reactions of Ru(Cp) complexes with P(o-tolyl)3

Reaction of [Ru(Cp^∗)(CH₃CN)₃](PF₆) with P(o-tolyl)₃ affords [Ru(Cp^∗){(η⁶-o-tolyl)P(o-tolyl)₂}](PF₆) (4) in which the P-atom is not coordinated to the metal. The solid-state structure of 4 has been determined. A related reaction with P(p-tolyl)₃ reveals a small quantity [Ru(Cp^∗){(η⁶-p-tolyl)P(o-tolyl)₂}](PF₆), in solution, but mostly the expected bis-phosphine complex. Reaction of the Ru(IV) dication, [Ru(Cp^∗)(η³-PhCHCHCH₂)(DMF)₂](PF₆)₂, with P(o-tolyl)₃ gives a mixture of the phosphonium salt, C₆H₅CHCHCH₂P(o-tolyl)₃ (9) and the dication [Ru(Cp^∗) (η⁶-C₆H₅CHCHCH₂P(o-tolyl)₃)](PF₆)₂ (10). Salt 9 forms via attack of the P-atom on the allyl ligand. The latter product results from complexation of 9 via the phenyl group of the former allyl ligand. It would seem that the sterically demanding P(o-tolyl)₃ ligand is not readily compatible with the Ru(Cp^∗) fragment, in either the +2 or +4 oxidation state. Detailed NMR studies are reported.     

Formation and stability of gaseous tolyl ions

Collisional activation mass spectra confirm that tolyl ions can be produced from a variety of CH₃C₆H₄Y compounds. High purity o-, m- and p-tolyl ions are prepared by chemical ionization of the corresponding fluorides (Y=F) as proposed by Harrison. In electron ionization of CH₃C₆H₄Y formation of the more stable tropylium and benzyl ionic isomers usually accompanies that of the o-, m- and p-tolyl ions. Isomerization of low energy [CH₃C₆H₄Y]⁺? to [Y–methylenecyclohexadiene]⁺? is proposed to account for most [benzyl]⁺ formation, while the tropylium ion appears to arise from the isomerization of tolyl ions formed with higher internal energies, [o-, m-, p-tolyl]⁺→ [benzyl]⁺→ [tropylium]⁺, consistent with Dewar's predictions from MINDO/3 calculations.     

Solid-State Properties of Hexaazatriphenylenehexacarbonitrile HAT(CN)6.− Radical Anions in Crystalline Salts Containing Cryptand(M+) and Crystal Violet Cations

Crystalline {Cryptand[2.2.2](Na⁺)}{HAT(CN)₆^.−}⋅0.5C₆H₄Cl₂ ( 1 ), {Cryptand[2.2.2](K⁺)}{HAT(CN)₆^.−} ( 2 ), (CV⁺){HAT(CN)₆^.−} ( 3 ), and (CV⁺){HAT(CN)₆^.−}⋅2C₆H₄Cl₂ ( 4 ) salts (where CV⁺ is the crystal violet cation) containing hexaazatriphenylenehexacarbonitrile radical anions have been obtained. The solid-state molecular structure as well as the optical and magnetic properties of HAT(CN)₆^.− are studied. The formation of HAT(CN)₆^.− in 1 – 4 leads to the appearance of new bands in the visible range, at 694 and 740 nm. The HAT(CN)₆^.− radical anions have spin state S=1/2 and are packed in one-dimensional stacks containing the {HAT(CN)₆^.−}₂ dimers alternated with weaker interacting pairs of HAT(CN)₆^.− in 1 and nearly isolated {HAT(CN)₆^.−}₂ dimers in 2 . The {HAT(CN)₆^.−}₂ dimers are diamagnetic in 1 but they effectively mediate one-dimensional antiferromagnetic coupling of spins within the stacks with moderate exchange interaction of J/k_B = −80 K. The behaviour of salt 2 is described by a singlet–triplet model for the {HAT(CN)₆^.−}₂ dimers with an energy gap of 434(±7) K. Magnetic behaviour of both salts agree well with the data of extended Hückel calculations. Salts 3 and 4 contain isolated stacks of alternated HAT(CN)₆^.− and CV⁺ ions, and in this case, nearly paramagnetic behaviour is observed with Weiss temperatures of −1 and −7 K, respectively. Narrow Lorentzian EPR signals with g = 2.0033–2.0039 were found for the HAT(CN)₆^.− radical anions in 1 and 4 but in solution g-factor shifts to 1.9964. The electronic structure of HAT(CN)₆^.− is analysed based on X-ray diffraction data for 2 , showing a Jahn–Teller distortion of the radical anion that reduces the symmetry from D_3h to C_s and splits the initially degenerated LUMOs.     

First Bis(σ)-borane Complexes of Group 6 Transition Metals: Experimental and Theoretical Studies

A series of bis(σ)-borane complexes of Group 6 transition metals were prepared by direct dihydroborane coordination to the metal center. Reaction of [M(CO)₃(PCy₃)₂] and two dihydroboranes [DurBH₂] and [(Me₃Si)₂NBH₂] (Dur=2,3,5,6-Me₄C₆H) yielded bis(σ)-borane complexes fac-[M(CO)₃(PCy₃){η²-(H₂BR)}] (R=Dur; 1 : M=Cr, 2 : M=W; R=N(SiMe₃)₂; 3 : M=Cr, 4 : M=W). In the case of molybdenum, we have isolated an arene complex ( 5 ) with [DurBH₂] in which the Dur group acts as a η⁶-bound ligand, and with [(Me₃Si)₂NBH₂] a similar bis(σ)-borane complex was isolated, cis,trans-[Mo(CO)₂(PCy₃)₂{η²-(H₂BN(SiMe₃)₂}] ( 6 ), with a different pattern of auxiliary ligands. The complexes were investigated by multinuclear NMR spectroscopy, mass spectrometry, X-ray diffraction analysis, and computational methods. Quantum theory of atoms in molecules (QTAIM) calculations demonstrated that the borane complexes may be described as pure bis(σ)-borane complexes rather than elongated or stretched examples given that the calculations do not show the presence of a ring-critical point (RCP) at the ring formed by the interactions of the B−H with metal center.     

Metal complexes of hybrid oxygen — arsenic ligands. Part I. Complexes ofo-dialkyl/arylarsinobenzoic acids with chromium(III)

Summary Reactions of hybrid oxygen-arsenic ligands:o-R₂As-C₆H₄CO₂H (R = Me, Et, C₆H₁₁, Ph andp-tolyl) with CrO₃ and of their sodium salts withtrans-[CrCl₂(H₂O)₄]Cl·2H₂O in a 31 molar ratio yield three types of oxo/hydroxo bridged complexes:a. CrO(o-R₂AsC₆H₄CO₂)nH₂O (R=Me, n=1.5 or 2.5; R=Et, n=1 or 1.5; R=C₆H₁₁, n=1 or 3; R=p-tolyl, n=4),b. Cr(o-Ph₂AsC₆H₄CO₂)₂(OH)2.5 H₂O andc. Cr(o-R₂AsC₆H₄CO₂)(OH)₂nH₂O (R=Ph, n=1; R=p-tolyl, n=0.5). Their i.r. data favour symmetrical chelation of the carboxylate ion, with the metal ion leaving the arsenic(III) uncoordinated. Suitable dimeric, trimeric and tetrameric structures have been assigned for (i) Typea (R=C₆H₁₁, n=1), (ii) Typea (R=p-tolyl, n=4) and (iii) typea. (R= Et, n=1), Typeb. and Typec. (R=p-tolyl, n=0.5) complexes respectively on the basis of solution spectra and experimental molecular weights and _eff values. Calculated ligand field parameters (10 Dq and B) for all the complexes indicate covalent interaction between the metal ion and the ligands.     

Remote Effect from Boron Cluster: Tunable Photophysical Properties of o-Carborane-Based Luminogens

We proposed a new molecular design strategy that the o-carboranyl group is attached as “an innocent unit” to the remote side of luminogens to tune photophysical properties. To verify this strategy, two o-carborane-based compounds with asymmetric molecular geometry were designed and synthesized. Photophysical properties of o-carborane-based luminogens were investigated on the basis of UV-Vis spectra, photoluminescence spectra, crystal structure analysis and theoretical calculations. The results indicate that the o-carboranyl group has a slight effect on the energy gap between the ground state (S₀) and the first excited state (S₁) in the solution state but a significant effect on the energy gap between S₀ and S₁ in the solid state. Besides, the radiative and non-radiative transition processes are modulated by the o-carboranyl unit. This leads to emission quenching in the solution state but an enhanced luminous efficiency in the aggregate state with a typical aggregation-induced emission (AIE) property.     

The reaction of diaryl derivatives of bis(triphenylphosphine)platinum(II) with [60]fullerene as a route to the platinum complex η2-C60Pt(PPh3)2

The reaction ofcis-Ar₂Pt(PPh₃)₂ (Ar=p-MeC₆H₄ (1a) and Ar=Ph (1b)) with [60]fullerene in toluene afforded the metal-fullerene complex η²-C₆₀Pt(PPh₃)₂ (2), which was isolated in the crystalline state. The reductive elimination between C₆₀ and1a or1b also resulted in the formation of biaryls (p-MeC₆H₄)₂ and Ph−Ph. The composition and structure of the compounds were established by¹H and³¹P NMR spectroscopy, electronic absorption spectroscopy, and elemental analysis. The homolytic phosphorylation of2 was additionally studied by the ESR method.     

Studies on intermolecular interactions of metal chelate complexes. V. copper(ii) dithiophosphate complexes: an example of an inner self-redox reaction

Summary Studies of copper dithiophosphate (dtp) complexes by various physical methods, in the solid and the molten state as well as in solution, are reported. In the solid state all the complexes of dithiophosphate (RO)₂PS ₂ ^– [R = C_nH_2n+1 (n=1–4), Ph, orcyclo-C₆H₁₁] are diamagnetic but in the molten state and in solution they are paramagnetic. Interconversions were found to be reversible, and the effect was ascribed to an inner self-redox reaction. Only the bulkyo-tolyl derivative is paramagnetic in the solid and molten states and in solution. It is proposed that the self-redox reaction involves association between two molecules of Cu^II(dtp)2 during crystallization, followed by formation of [Cu^I(dtp)]₂, and (RO)₂P(S)S-S(S)P(OR)₂, and then [Cu^I(dtp)]₄. The molecular structures of complexes with R = isopropyl ando-tolyl confirm these inferences.Part IV of this series: N. D. Yordanov, V. Iliev, and D. Shopov,Inorg. Chim. Acta, 60, 21 (1982).     

Synthesis,crystal structures and electrocatalytic properties of bridgehead-C-functionalized diiron dithiolate complexes

To investigate the influence of bridgehead-C functionality in diiron dithiolate complexes on the molecular structure and electrocatalytic properties of [FeFe]-hydrogenase models, three new bridgehead-C-functionalized model complexes 1–3 have been synthesized and structurally characterized. Treatments of parent complex [(μ-SCH₂)₂CHCO₂H][Fe₂(CO)₆] (A) with the esterification agents o-MeC₆H₄OH, p-ClC₆H₄OH, or p-HOC₆H₄CHO in the presence of 4-dimethylaminopyridine and dicyclohexylcarbodiimide in CH₂Cl₂ at room temperature resulted in formation of [(μ-SCH₂)₂CHCO₂R][Fe₂(CO)₆] (R = o-MeC₆H₄–, 1; p-ClC₆H₄–, 2; p-OHCC₆H₄–, 3) in 53–55% yields. The new complexes 1–3 were characterized by elemental analysis, IR and NMR spectroscopy, and especially determined by X-ray crystallography. The electrochemical properties of 1–3 and the electrocatalytic H₂ evolution catalyzed by 1 have been investigated by cyclic voltammetry, where 1 is a catalyst for HOAc proton reduction to H₂ under electrochemical conditions.     

Studies on DNA binding behavior of biologically active Cu(II) complexes of Schiff bases containing acyl pyrazolones and 2-ethanolamine

Pyrazolone derivatives (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one [PMP-EA] (1), (Z)-1-(3-chlorophenyl)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1H-pyrazol-5(4H)-one [MCPMP-EA] (2), and (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-p-tolyl-1H-pyrazol-5(4H)-one [PTPMP-EA] (3) have been synthesized and characterized. The molecular geometry of 2 has been determined by single-crystal X-ray study. These ligands exist in amine-one tautomeric form in the solid state. Three copper(II) complexes, [Cu(PMP-EA)(H₂O)₂] (4), [Cu(MCPMP-EA)(H₂O)₂] (5), and [Cu(PTPMP-EA)(H₂O)₂] (6), respectively, have been synthesized using these ligands and characterized by microanalytical data, molar conductivity, IR, UV–Visible, FAB-Mass, magnetic measurement, TG-DTA studies, and ESR spectral studies; Cu(II) is five-coordinated with [ML(H₂O)₂] composition. The interaction of the complexes with CT-DNA (calfthymus) was investigated using different methods. The results suggest that the copper complexes bind to DNA via intercalation and can quench the fluorescence intensity of EB bound to DNA.     

Synthesis and molecular structure of 6-aryl-3-ethoxycarbonyl-4-hydroxypyridazines

EthylZ-5-aryl-2-diazo-5-hydroxy-3-oxopent-4-enoates interact with triphenylphosphine to give 6-aryl-3-ethoxycarbonyl-4-hydroxypyridazines (Ar=Ph, 4-MeC₆H₄, 4-ClC₆H₄). Quantum-chemical calculations (MNDO) were performed to estimate the tautomeric equilibrium in the latter using a 6-phenyl-substituted derivative as an example. Acetylation of the 4-hydroxypyridazines led to 4-acetoxy-6-aryl-3-ethoxycarbonylpyridazines. The structure of the latter was confirmed by an X-ray diffraction analysis of 4-acetoxy-3-ethoxycarbonyl-6-(p-tolyl)pyridazine. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2260–2263, December, 1997.     

Metal complexes of hybrid oxygen-arsenic ligands Part II: Complexes ofo-dialkyl/arylarsinobenzoic acids with cobalt(II) and nickel(II)

Summary Reactions of hybrid oxygen-arsenic ligandso-R₂As-C₆H₄CO₂H (R=Et, C₆H₁₁ andp-tolyl) (2 mols) with M(OAc)₂ · 4H₂O (M=Co or Ni) (1 mol) yield Co(o-R₂As-C₆H₄CO₂)₂ (R=Et orp-tolyl) and Ni(o-R₂AsC₆H₄CO₂)₂ · nH₂O (R=Et, n=0.5; R=C₆H₁₁, n=2) complexes. The electronic spectra and magnetic susceptibilities at different temperatures are compatible with tetrahedral and octahedral stereochemistries for cobalt(II) and nickel(II) complexes respectively. The ligand field parameters (10 Dq and B) have also been calculated and interpreted in terms of metal-ligand bond types.     

Reduction of aromatic nitro compounds with NaBH4 catalysed by nickel complexes ofo-aminothiophenol Schiff base derivatives

Summary The nickel complexes of Schiff bases formed fromo-aminothiophenol and -dicarbonyl compounds, Ni(o-SC₆H₄N=CRCR=NC₆H₄S-o) (R=H, Me, Ph) (1a-c), catalyse the reduction of aromatic nitro compounds by NaBH₄. The reduced species [Ni(o-SC₆H₄N=CHCH=NC₆H₄S-o)]^– (2) and [Ni(o-SC₆H₄NHCH₂CH=NC₆H₄S-o)]^– (3) were identified as intermediates in the catalytic cycle.     

Tridentate chelate π-bonded complexes of rhodium(I), iridium(I), and iridium(III) and chelate σ-bonded complexes of nickel(II), palladium(II), and platinum(II) formed by intramolecular hydrogen abstraction reactions

2,2′-Bis(o-diphenylphosphino)bibenzyl, o-Ph₂PC₆H₄CH₂CH₂C₆H₄PPh₂-o (bdpbz), is dehydrogenated by various rhodium complexes to give the planar rhodium(I) complex

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, from which the ligand, 2,2′-bis(o-diphenylphosphino)-trans-stilbene (bdpps) can be displaced by treatment with sodium cyanide. The stilbene forms stable chelate olefin complexes with planar rhodium(I) and iridium(I) and with octahedral iridium(III). On reaction with halide complexes of nickel(II), palladium(II) or platinum(II), the stilbene ligands

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(R = Ph or o-CH₃C₆H₄) lose a vinyl proton in the form of hydrogen chloride to give chelate, planar σ-vinyls of general formula =CHC₆H₄PR₂-o) (M = Ni, Pd, Pt; X = Cl, Br, I) of high thermal stability; analogous methyl derivatives =CHC₆H₄PR₂-o) are obtained from Pt(CH₃)₂(COD) (COD = 1,5-cyclooctadiene) and the stilbene ligands. The bibenzyl also forms chelate σ-benzyls HCH₂C₆H₄PPh₂-o) (M = Pd, Pt; X = Cl, Br, I). The ¹H NMR spectra of the o-tolyl methyl groups in the compounds =CHC₆H₄PR₂-o) (M = Ni, Pd, Pt; R = o-CH₃C₆H₄) vary with temperature, probably as a consequence of interconversion of enantiomers arising from restricted rotation about the M---P and M---C bonds. Possible mechanisms for the dehydrogenation reactions are briefly discussed.     

Lanthanide chelates of fluorinated β-diketones. Part III. Mass spectra of lanthanide chelates of five fluorinated β-diketones

Summary The mass spectra of sixty lanthanide chelates of the fluorinated -diketones RC(OH)=CHCOCF₃ (R=2-theonyl,p-BrC₆H₄,m-MeC₆H₄,o-MeC₆H₄, and Bu-t) have been obtained. The mass spectra were essentially similar, in contrast to those found ford-block transition metal chelates. Valency change from 3 to 2 occurred with samarium (4f ⁵), europium (4f ⁶), thulium (4f ¹²), and ytterbium (4f ¹³); the intensity of the Met(II)-containing peaks varied: Eu Sm > Yb > Tm, reflecting the decreasing tendency of these lanthanides to display bivalency. Valency change from 4 to 3 was observed with cerium (4f¹) but not with terbium (4f⁸).Part II,Transition Met. Chem., 9, 423 (1984).     

Reaction of (η5‐C5H5)Fe(CO)2I with Anionic Bidentate Phosphine Ligands PPh2(o‐C6H4NHLi) or PPh2(o‐C6H4OLi)

The o‐substituted hybrid phenylphosphines, PPh₂(o‐C₆H₄NH₂) and PPh₂(o‐C₆H₄OH), could be deprotonated with LDA or n‐BuLi to yield PPh₂(o‐C₆H₄NHLi) and PPh₂(o‐C₆H₄OLi), respectively. When added to a solution of (η⁵‐C₅H₅)Fe(CO)₂I at room temperature, these two lithiated reagents produce a chelated neutral complex 1 (η⁵‐C₅H₅)Fe(CO)[C(O)NH(o‐C₆H₄)PPh₂‐C,P‐η²] for the former and mainly a zwitterionic complex 2 , (η⁵‐C₅H₅)Fe⁺(CO)₂[PPh₂(o‐C₆H₄O^?)] for the latter. Complex 1 could easily be protonated and then decarbonylated to give 4 [(η⁵‐C₅H₅)Fe(CO){NH₂(o‐C₆H₄)PPh₂‐N,P‐η²}⁺]. Complexes 1 and 4‐I have been crystallographically characterized with X‐ray diffraction.     

Synthesis and Structures of cis- and trans-[Os(Bcat)(aryl)(CO)2(PPh3)2]: Compounds of Relevance to the Metal-Catalyzed Hydroboration Reaction and the Metal-Mediated Borylation of Arenes

Support for key steps of the mechanism for the transition metal catalyzed hydroboration reaction is provided by the characterization and reactions of 1 , a cis-(boryl)(aryl) complex of osmium(II ). This compound readily eliminates o-tolylBcat to give the osmium(0) intermediate 2 , which in the presence of HBcat reestablishes the osmium–boron bond by forming 3 . R=o-tolyl, H₂cat=catechol=1,2-(HO)₂C₆H₄.     

A Diruthenium Complex of an N-Pyridyl-o-aminophenol Derivative: A Route to Mixed Valency

An N-pyridyl-o-aminophenol derivative that stabilises mixed-valence states of ruthenium ions is disclosed. A diruthenium complex, [(L_IQ⁰)Ru₂Cl₅] ⋅ MeOH ( 1⋅ MeOH) is successfully isolated, in which L_IQ⁰ is the o-iminobenzoquinone form of 2-[(3-nitropyridin-2-yl)amino]phenol (L_APH₂). In 1 , L_IQ⁰ oriented towards one ruthenium centre is a non-innocent NO-donor redox ligand, whereas another oriented towards another ruthenium centre is an innocent pyridine-donor redox ligand. Complex 1 is a diruthenium(II,III) mixed-valence complex, [Ru^II(L_IQ⁰)(μ-Cl)₂Ru^III], with a minor contribution from the diruthenium(III,III) state. [Ru^III(L_ISQ^.−)(μ-Cl)₂Ru^III] contains L_ISQ^.−, which is the o-iminobenzosemiquinonate anion radical form of the ligand. Complexes 1 ⁻ and 1 ⁺ are diruthenium(II,II), [Ru^II(L_IQ⁰)(μ-Cl)₂Ru^II], and diruthenium(III,III), [Ru^III(L_IQ⁰)(μ-Cl)₂Ru^III], complexes, respectively, of L_IQ⁰. Complex 1 ²⁻ is a diruthenium(II,II) complex of the o-iminobenzosemiquinonate anion radical (L_ISQ^.−), [Ru^II(L_ISQ^.−)(μ-Cl)₂Ru^II], with a minor contribution from the diruthenium(III,II) form, [Ru^III(L_AP²⁻)(μ-Cl)₂Ru^II]. Complex 1 ²⁺ is a diruthenium(III,IV) mixed-valence complex of L_IQ⁰, [Ru^III(L_IQ⁰)(μ-Cl)₂Ru^IV]. Complexes 1 and 1 ²⁺ exhibit inter-valence charge-transfer transitions at λ=1300 and 1370 nm, respectively.