Synthesis,crystal structures and electrochemical properties of group 6 metal carbonyl anion complexes

A series of [M(CO)₅I]⁻ and [M₂(CO)₁₀I]⁻ anion complexes have been synthesized by the photochemical reaction of PhCH₂N(CH₃)₃I or FcCH₂N(CH₃)₃I (Fc=ferrocenyl) with M(CO)₆ (M = Cr, Mo or W), and characterized by elemental analyses, i.r., ¹H-n.m.r. and ¹³C-n.m.r. spectra in the case of the molybdenum and tungsten complexes. These complexes exhibit considerably different electrochemical behavior, when investigated by cyclic voltammetry. The crystal structures of [PhCH₂N(CH₃)₃][Cr(CO)₅I] and [FcCH₂N(CH₃)₃][W₂(CO)₁₀I] have been determined by X-ray diffraction, indicating that only weak contacts maybe exist between anions and cations by the I...H bond in the former, and there are no direct interactions between anions and cations in the latter.     

Group 6-group 10 heterobimetallic complexes with sulfur ligands

Complexes that contain both a group 6 group 10 metal combination and a sulfur bound ligand form a growing set of species. Their chemistry is discussed and reviewed. Ligands that bind to such heterobimetallic molecules most commonly are S^2– and SR^– species. Metal-metal bonded complexes, and compounds where metal-metal interactions are minimal are both discussed. The structural parameters for many of the crystallographically characterized complexes are tabulated.     

Organometallic dithiolene complexes of the group 8-10 metals: reactivities, structures and electrochemical behavior

Research progress in the organometallic dithiolene complexes such as [Cp(or Cp*)M(dithiolene)] (M = Co, Rh, Ir, Ni), [(C(6)R(6))Ru(dithiolene)] and [(C(4)R(4))Pt(dithiolene)] complexes during the past decade is described and the reactivities, structures and electrochemical behavior are summarized in this paper. The five-membered metalladithiolene ring (MS(2)C(2)) undergoes addition reactions to the M[double bond, length as m-dash]S bond to form 18-electron adducts by an imido, alkylidene, alkene or norbornene group and also undergoes dimerizations on the basis of the unsaturation in the ring. The aromaticity of the ring causes substitution reactions on the dithiolene carbon by a C-centered radical, S-centered radical or succinimide group when the ring has a C-H bond. Furthermore a dithiolene-dithiolene homo-coupling reaction by an acid or dithiolene-aryl cross-coupling occurs based on the aromaticity in the ring. Dissociations of the 18-electron adducts are observed by those thermolyses, photolyses, electrochemical redox reactions and other chemical reactions with tertiary phosphorus compounds. One representative example of them is the imido adduct dissociation with PR(3) under heating toward the intramolecular imido migration to a Cp ligand. Since all products are rearomatized by those adduct dissociations, it is concluded that the 'coexistence of aromaticity and unsaturation' in the metallacycle mediates the diverse chemical reactions.     

Novel heterodinuclear transition metal macrocyclic complexes: syntheses,characterization and crystal structures

Two unsymmetrical, macrocyclic, heterodinuclear complexes, [Cu^IIM^II(L)]?(ClO₄)₂·nH₂O (n?=?3; M?=?Zn, Cd) have been obtained by cyclocondensation of N,N′-bis(3-formyl-5-n-butylsalicylidene)ethylenediimine and 1,3-diaminopropane in the presence of M²⁺. The structures of both complexes were determined by X-ray diffraction techniques. In each complex, two metals are located in the tetraimine macrocyclic cavity, and a water molecule and a perchlorate group are separately coordinated to the metal ions on the same side of the ring. Coordination geometry around each metal is approximately square pyramidal. ESMS spectra were used to characterize the complexes and isotopic distributions were investigated.     

Synthesis and characterization of group 6-9 metal-rich homo- and hetero-metallaboranes

To isolate the metal-rich metallaboranes of group 6-9, we have performed the reaction of various reaction intermediates, generally synthesized from the low-temperature reactions of [Cp1WCl₄] (Cp1 ​= ​η⁵-C₅Me₅), [(Cp1RhCl₂)₂], or [(Cp1RuCl₂)₂] and [LiBH₄ THF] with different transition metal carbonyl compounds. For example, the thermolytic reaction of [Fe₂(CO)₉] with an in situ generated intermediate, produced from the reaction of [Cp1WCl₄] and [LiBH₄THF] afforded a trigonal bipyramidal cluster, [(μ₃-BH)₂H₂{Cp1W(CO)₂}{Cp1W(CO)}{Fe(CO)₃}], 1 which contains a triply-bridging bis-{hydrido(borylene)} ligand. Similarly, the reaction of [Co₂(CO)₈] with nido-[(RhCp1)₂(B₃H₇)] I at room temperature, yielded an octahedral cluster, [(Cp1Rh)₂B₂H₂Co₂(CO)₅(μ₃-CO)], 2. In this reaction, nido-I having (n+2) skeletal electron pairs (SEP) goes on for the formation of a closo-rhodaborane with (n+1) SEP. In addition, we have isolated a trinuclear bis(μ₃-oxo) metalla cluster [(Cp1Ru)₃(μ₃-OBF₃)₂(μ-H)], 3. Compound 3 can be considered as cluster having trigonal bipyramidal geometry with exo-BF₃ fragment. All these clusters were characterized by IR, mass spectrometry, NMR, and single-crystal X-ray crystallographic analysis.     

Electronic structures of tetragonal nitrido and nitrosyl metal complexes

The standard oxidation states of central metal atoms in C _4v nitrido ([M(N)(L)₅] ^z ) complexes are four units higher than those in corresponding nitrosyls ([M(NO)(L)₅] ^z ) (L=CN: z = 3−, M = Mn, Tc, Re; z = 2−, M = Fe, Ru, Os; L = NH₃: z = 2+, M = Mn, Tc, Re; z = 3+, M = Fe, Ru, Os). Recent work has suggested that [Mn(NO)(CN)₅]³⁻ behaves electronically much closer to Mn(V)[b ₂(xy)]², the ground state of [Mn(N)(CN)₅]³⁻, than to Mn(I)[b ₂(xy)]²[e(xz,yz)]⁴. We have employed density functional theory and time-dependent density functional theory to calculate the properties of the ground states and lowest-lying excitations of [M(N)(L)₅] ^z and [M(NO)(L)₅] ^z . Our results show that [M(N)(L)₅] ^z and [M(NO)(L)₅] ^z complexes with the same z value have strikingly similar electronic structures.     

Synthesis, characterization, solid-state molecular structures, and deprotonation reactions of cationic alcohol complexes of osmium nitrosyl porphyrins

New alkoxide (OEP)Os(NO)(OR) (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion; R = ethyl, isopropyl, hexyl, cyclohexyl) compounds and alcohol [(OEP)Os(NO)(HOR)]+ complexes (R = methyl, ethyl, isopropyl, hexyl, cyclohexyl) have been prepared in high yields and have been fully characterized by IR, 1H NMR, and UV-vis spectroscopy, and by elemental analyses. The (OEP)Os(NO)(OEt) compound was characterized by single-crystal X-ray crystallography. The cationic aqua and alcohol [(OEP)Os(NO)(HOR)]+ complexes (R = ethyl, isopropyl, hexyl) complexes were also characterized by single-crystal X-ray crystallography, and the latter represent the first osmium alcohol structures to be reported. The electrophilic [(OEP)Os(NO)]+ cation in the [(OEP)Os(NO)(HOR)]+ complexes renders the coordinated alcohol ligands susceptible to deprotonation by pyridine to produce the corresponding alkoxide (OEP)Os(NO)(OR) derivatives. A one-pot reaction sequence for the preparation of new (OEP)Os(NO)(OR) complexes from (OEP)Os(NO)(OEt) was developed, which was based on (i) initial protonation of the ethoxide compound to give [(OEP)Os(NO)(HOEt)]+, (ii) alcohol substitution by ROH to give [(OEP)Os(NO)(HOR)]+, and (iii) deprotonation of the latter by pyridine to give (OEP)Os(NO)(OR).     

Synthesis, structures and photoluminescence behavior of some group 10 metal alkynyl complexes derived from 3-(N-carbazolyl)-1-propyne

A new class of luminescent and thermally stable mononuclear group 10 platinum(II) and palladium(II) acetylides trans-[Pt(PR₃)₂(L)₂] (R = Bu, Et) and trans-[Pd(PBu₃)₂(L)₂] (LH = 3-(N-carbazolyl)-1-propyne) have been successfully synthesized and characterized. The structural properties of these discrete metal complexes have been studied by X-ray crystallography. We report their optical absorption and photoluminescence spectra and interpret the results in terms of the nature of the metal center and the type of phosphines used. Our investigations indicate that they display heavy metal-enhanced phosphorescence bands at 77 K and we find that the platinum complexes afford more intense triplet emission than that for the palladium congener, consistent with the stronger heavy-atom effect of the third row element than the second row neighbor of the same group.     

Synthesis, structures, and luminescent properties of phenol-pyridyl boron complexes

Syntheses of the four mixed phenol-pyridine derivatives 1,6-bis(2-hydroxyphenyl)pyridyl boron naphthalene (1), 1,6-bis(2-hydroxy-5-methylphenyl)pyridyl boron naphthalene (2), 1,6-bis(2-hydroxyphenyl)pyridyl boron 2-methoxylbenzene (3), and 1,6-bis(2-hydroxy-5-methylphenyl)pyridyl boron 2-methoxylbenzene (4) are reported. The structures of the boron compounds 1, 3, and 4 were determined by single-crystal X-ray diffraction. The molecular packing is characterized by intermolecular pi...pi and hydrogen-bonding interactions. DSC analysis demonstrates that 1 and 2 have good thermal stability with higher glass transition temperatures (Tg) and melting points (Tm) than 3 and 4. Boron complexes 1-4 display bright blue luminescence in solution and the solid state. White and blue electroluminescent (EL) devices were fabricated successfully using these boron compounds.     

Synthesis, structures, and magnetic properties of tetranuclear CuII-LnIII complexes

The copper(II)-gadolinium(III) and copper(II)-terbium(III) complexes studied in this report derive from disymmetric trianionic ligands abbreviated H3Li (i = 4-6). These ligands are obtained through reaction of different aldehydes with "half-units" having an amide function, the latter resulting from the monocondensation of different diamines with phenyl 2-hydroxy-3-methoxybenzoate. Upon deprotonation, the Li ligands (i = 4-10) possess an inner N2O2 coordination site with one amido, one imine, and two phenoxo functions, an outer O2O2 or O2O coordination site, and an amido oxygen atom positioned out of these two sites. The trianionic character of such ligands yields original anionic complexes in the presence of copper(II) or nickel(II) ions, with a 1/1 L/M stoichiometry. The crystal and molecular structures of four complexes, two 3d (1, 5) and two 3d-4f (12, 13) complexes, have been determined. Complex 1 crystallizes in the monoclinic space group C2/c: a = 27.528(2) A, b = 7.0944(7) A, c = 22.914(2) A, beta = 92.130(6) degrees , V = 4471.9(7) A(3), Z = 8 for C(21.5)H(27)CuKN(2)O(6.5). Complex 5 crystallizes in the monoclinic space group P2(1)/n (No. 14): a = 11.0760(9) A, b = 21.454(2) A, c = 15.336(1) A, beta = 101.474(1) degrees , V = 3571.5(5) A(3), Z = 4. Complex 12 crystallizes in the triclinic space group P (No. 2): a = 8.682(2) A, b = 11.848(2) A, c = 11.928(2) A, alpha = 81.77(3) degrees , beta = 89.17(3) degrees , gamma = 85.49(3) degrees , V = 1210.6(4) A(3), Z = 2 for C20H22CuN5O11Tb. Complex 13 belongs to the monoclinic space group C2/c: a = 25.475(5)A, b = 12.934(3)A, c = 15.023(3) A, beta = 91.06(3) degrees , V = 4949.02A3, Z = 8 for C21H25CuN4O12Tb. The structural determinations confirm that the dinuclear entities involved in 12 and 13 are disposed in a head-to-tail arrangement to give tetranuclear complexes in which the copper and lanthanide ions are positioned at the vertexes of a rectangle. In the [Cu-Gd]2 species, there are two different ferromagnetic Cu-Gd interactions. The stronger one is supported by the double phenoxo bridge (CuO2Gd) while the weaker one corresponds to the single amido bridge (Cu-N-C-O-Gd). Replacement of gadolinium ions with anisotropic terbium ions yields tetranuclear entities showing slow relaxation of magnetization and magnetization hysteresis. Detailed relaxation and hysteresis loop studies establish single-molecule magnet (SMM) behavior which is influenced by weak intermolecular interactions.     

Synthesis,structures and magnetic properties of two hexanuclear complexes

The reaction of salicylaldoxime (H₂salox) with Mn(ClO₄)₂ · 6H₂O, NaN(CN)₂ and NEt₃ in MeOH affords a Mn^III₆ hexanuclear complex of [Mn₆O₂(salox)₆(MeOH)₆(NCNCONH₂)₂] (1), while reaction of H₂salox with MnCl₂ · 4H₂O and NEt₄OH in EtOH affords a Mn^III₆ hexanuclear complex of [Mn₆O₂(salox)₆(EtOH)₄(H₂O)₂Cl₂] (2). Both complexes 1 and 2 contain a [Mn^III₆(μ₃-O)₂]¹⁴⁺ core, which is a known structural type in the family of Mn₆ complexes. Variable temperature magnetic susceptibilities and magnetization measurement of complexes 1 and 2 have been carried out. Exchange interactions of metal centers for complexes 1 and 2 are fitted by a full diagonalization matrix method. The fitting results indicate that both complexes 1 and 2 have the ground-state spin value of S = 4, and the ground state of complex 1 has the much closer energy to low-lying spin states than that of complex 2. Magnetization measurements at 2.0–4.0 K and 10–70 kG confirm that the ground state is S = 4, with significant magnetoanisotropy as gauged by the D value of ?0.82 cm^?1 and ?1.18 cm^?1, for 1 and 2, respectively. The frequency dependence of the out-of-phase component in alternating current magnetic susceptibilities for both complexes 1 and 2 indicates the slow magnetic relaxation of superparamagnetic behaviour with a U_eff of 27.0(1) K and τ₀ = 3.8(2) × 10^?9 s for complex 1, and U_eff of 25.1(6) K and τ₀ = 4.6(1) × 10^?8 s for complex 2.     

Synthesis, structures, magnetism and electrochemical properties of triruthenium-acetylide complexes

A series of triruthenium complexes with arylacetylide axial ligands Ru(3)(dpa)(4)(C(2)X)(2)(BF(4))(y)(dpa = dipyridylamido; X = Fc, y= 0 (1); X = Ph, y= 0 (2); X = PhOCH(3), y= 1 (3); X = PhC(5)H(11), y= 1 (4); X = PhCN, y= 0 (5); X = PhNO(2), y= 0 (6)) have been synthesized. The crystal structures show that the Ru-Ru bond lengths (2.3304(9)-2.3572(5)A) of these compounds are longer than those of Ru(3)(dpa)(4)Cl(2)(Ru-Ru=2.2537(1)A). This is ascribed to the formation of the stronger pi-backbonding from metal to axial ligand which weakens the Ru-Ru interactions and the bond order is reduced in the triruthenium unit. Cyclic voltammetry and differential pulse voltammetry show that compound exhibits electronic coupling between the two ferrocenyl units with DeltaE(1/2) close to 100 mV. Compounds 2-6 display three triruthenium-based reversible one-electron redox couples, two oxidations and one reduction, and the electrode potentials shift upon varying the substituents. A linear relationship is observed when the Hammett constants are plotted against the redox potentials.     

Synthesis and properties of Zr-Co heterodinuclear complexes with a bridging bis(cyclopentadienyl) ligand

[(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(C₅H₅)] reacted with Co₂(CO)₈ to produce a heterodinuclear Zr(IV)-Co(I) complex [(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(η⁵-C₅H₄)Co(CO)₂] (3). Complex 3 underwent oxidative addition of I₂ to give [(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(η⁵-C₅H₄)CoI₂(CO)] (4) having Zr(IV) and Co(III) centers. The carbonyl ligand of 4 was easily replaced with P(OMe)₃ and PPh₃ to afford [(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(η⁵-C₅H₄)CoI₂(L)] (5: L = P(OMe)₃, 6: L = PPh₃). Structures of 5 and 6 were determined by X-ray crystallography. These Zr-Co heterodinuclear complexes catalyzed polymerization of ethylene and propylene.     

Synthesis, characterization and molecular structures of six-coordinate manganese nitrosyl porphyrins

Manganese(II) porphyrins are isoelectronic with iron(III) porphyrins, and previously reported work suggests that manganese nitrosyl porphyrins are good structural models for their kinetically unstable and biologically relevant ferric-NO analogues. We have prepared a new set of six-coordinate manganese nitrosyl porphyrins of the general form (por)Mn(NO)(L)(por = TTP, T(p-OCH3)PP; L = piperidine, methanol, 1-methylimidazole) in moderate to high yields. The (por)Mn(NO)(pip) complexes were prepared from the reductive nitrosylation of the (por)MnCl compounds with NO in the presence of piperidine. The IR spectra of the (por)Mn(NO)(pip) compounds as KBr pellets show new strong bands at 1746 cm(-1)(for TTP) and 1748 cm(-1)(for (T(p-OCH3)PP) due to the NO ligands. Attempted crystallization of one of these compounds (por = TTP) from dichloromethane-methanol resulted in the generation of the methanol complex (TTP)Mn(NO)(CH3OH). Reaction of the (por)Mn(NO)(pip) compounds with excess 1-methylimidazole gave the (por)Mn(NO)(1-MeIm) derivatives in good yields. The IR spectra of these compounds show nu(NO) bands that are approximately 12 cm(-1) lower than those of the (por)Mn(NO)(pip) precursors, indicative of greater Mn-->NO pi-backdonation in the 1-MeIm derivatives. X-Ray crystal structures of three of these compounds, namely (TTP)Mn(NO)(CH3OH), (TTP)Mn(NO)(1-MeIm) and (T(p-OCH3)PP)Mn(NO)(1-MeIm) were obtained, and reveal that the NO ligands in these complexes are linear.     

New lanthanide-based complexes constructed from cucurbit[6]uril: Synthesis,structures and properties

Three lanthanide-based complexes, {Gd₂(H₂O)₁₀(CB[6])₂}·CB[6]·6Cl·12H₂O (1), {[Gd₂(H₂O)₈CB[6]₂]·(CuCl₄)·4Cl·46H₂O}_n (2), and {Dy₂(NO₃)₂(H₂O)₁₀(CB[6])}·4NO₃·14H₂O (3) (CB[6] = cucurbit[6]uril), were prepared with cucurbit[6]uril (CB[6]). These complexes were characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR spectroscopy, UV–Vis spectroscopy, thermogravimetric analysis and magnetization measurements. Crystallographic results showed that 1 and 3 are dinuclear and crystallize in the triclinic space group Pī, whereas 2 is a 1-D zigzag supramolecular chain that crystallizes in the monoclinic system in C2/c. The results indicated that temperature has a big effect on the supramolecular assemblies and a different structure inducer also leads to the formation of different coordination polymers. Frequency dependence in the ac susceptibility signals was observed in 3.     

Synthesis, crystal structures and magnetic properties of cyanide-bridged macrocyclic complexes

Three cyanide-bridged dodecanuclear macrocyclic wheel-like complexes [Cr(bpmb)(CN)₂]₆[Mn(5-Brsalpn)]₆·12H₂O (1), [Co(bpmb)(CN)₂]₆[Mn(5-Brsalpn)]₆·12H₂O (2) and [Co(bpmb)(CN)₂]₆[Mn(5-Clsalpn)]₆·24H₂O·8CH₃CN (3) [bpmb²⁻= 1,2-bis(pyridine-2-carboxamido)-4-methylbenzenate dianion; 5-Brsalpn²⁻ = N,N′-propylenebis(5-bromosalicylideneaminato) dianion; 5-Clsalpn²⁻ = N,N′-propylenebis(5-chlorosalicylideneaminato) dianion] have been synthesized and their crystal structures and magnetic properties have been investigated. The three compounds are structurally isomorphous and consist of alternating Mn(III)-Schiff base cations and [M(bpmb)(CN)₂]⁻ anions, generating cyanide-bridged nanosized dodecanuclear macrocyclic structures with an approximate diameter of 2 nm. The study of the magnetic properties of complex 1 reveals an antiferromagnetic interaction between the Cr(III) and Mn(III) ions through the cyanide bridges. A best-fit to the magnetic susceptibility of the complex leads to a magnetic coupling constant of J _CrMn = −2.65(6) cm⁻¹ on the basis of a one-dimensional alternating chain model with the Hamiltonian $ H = - J_{CrMn} \sum\limits_{i = 0}^N {S_i \cdot S_{i + 1} } $ H = - J_{CrMn} \sum\limits_{i = 0}^N {S_i \cdot S_{i + 1} } .     

氰根桥联大环配合物的合成、结构与磁性研究

合成了三个氰根桥联的十二核大环齿轮状配合物[Cr（bpmb）（CN）2]6-[Mn（5-Brsalpn）]6·12H2O（1）、[Co（bpmb）（CN）2]6[Mn（5-Brsalpn）]6·12H20（2）和[Co（bpmb）-（CN）2]6[Mn（5-Clsalpn）]6·24H20·8CH3CN（3）（bpmb^2-=1,2-bis（pyridine·2-carboxamido）-4-methylbenzenate）,表征了其晶体结构和磁性．三配合物是同晶型的,包含交替排列的锰（Ⅲ）-Schiff碱阳离子和[M（bpmb）（CN）2]-阴离子,阴阳离子单元用氰根离子连成十二核环状结构．分子环直径约2nm．配合物1呈反铁磁性,说明通过氰根桥铬（Ⅲ）．锰（Ⅲ）离子间存在反铁磁相互作用．基于一维交替链模型（哈密顿算符H=-JCrMnN∑i=0Si·Si＋1）导出的磁化率公式与实验数据进行拟和得到磁耦合参数JCrMn=-2．65（6）cm^-1．     

Synthesis, structures, and magnetic properties of face-sharing heterodinuclear Ni(II)-Ln(III) (Ln = Eu, Gd, Tb, Dy) complexes

Heterodinuclear [(Ni (II)L)Ln (III)(hfac) 2(EtOH)] (H 3L = 1,1,1-tris[(salicylideneamino)methyl]ethane; Ln = Eu, Gd, Tb, and Dy; hfac = hexafluoroacetylacetonate) complexes ( 1.Ln) were prepared by treating [Ni(H 1.5L)]Cl 0.5 ( 1) with [Ln(hfac) 3(H 2O) 2] and triethylamine in ethanol (1:1:1). All 1.Ln complexes ( 1.Eu, 1.Gd, 1.Tb, and 1.Dy) crystallized in the triclinic space group P1 (No. 2) with Z = 2 with very similar structures. Each complex is a face-sharing dinuclear molecule. The Ni (II) ion is coordinated by the L (3-) ligand in a N 3O 3 coordination sphere, and the three phenolate oxygen atoms coordinate to an Ln (III) ion as bridging atoms. The Ln (III) ion is eight-coordinate, with four oxygen atoms of two hfac (-)'s, three phenolate oxygen atoms of L (3-), and one ethanol oxygen atom coordinated. Temperature-dependent magnetic susceptibility and field-dependent magnetization measurements showed a ferromagnetic interaction between Ni (II) and Gd (III) in 1.Gd. The Ni (II)-Ln (III) magnetic interactions in 1.Eu, 1.Tb, and 1.Dy were evaluated by comparing their magnetic susceptibilities with those of the isostructural Zn (II)-Ln (III) complexes, [(ZnL)Ln(hfac) 2(EtOH)] ( 2.Ln) containing a diamagnetic Zn (II) ion. A ferromagnetic interaction was indicated in 1.Tb and 1.Dy, while the interaction between Ni (II) and Eu (III) was negligible in 1.Eu. The magnetic behaviors of 1.Dy and 2.Dy were analyzed theoretically to give insight into the sublevel structures of the Dy (III) ion and its coupling with Ni (II). Frequency dependence in the ac susceptibility signals was observed in 1.Dy.     

Synthesis, structures and properties of a new series of platinum-diimine-dithiolate complexes

The new square-planar platinum-diimine-dithiolate compounds [Pt(mesBIAN)SS] have been synthesised {mesBIAN = bis(mesityl)biazanaphthenequinone; SS = 1,2-dithiooxalate (dto) , maleonitriledithiolate (mnt) , 1,2-benzenedithiolate (bdt) , 3,4-toluenedithiolate (tdt) and 1,3-dithia-2-thione-4,5-dithiolate (dmit) }, and the X-ray crystal structures of and determined. Cyclic voltammetry reveals that all the compounds form stable anions, and ESR spectroscopy of these anions shows that the SOMO is based upon the mesBIAN ligand; compounds also show a reversible oxidation wave in their CV. Computational studies reveal that charge-transfer processes from orbitals that are combinations of metal and dithiolate ligand to a mesBIAN pi-based LUMO are responsible for the low energy absorptions seen in the UV/visible spectra of these compounds, and that the reverse process is responsible for the observed room-temperature solution luminescence of [Pt(mesBIAN)Cl(2)] and , and . Compounds and , containing aromatic thiolates, were not found to luminesce under the same conditions. Resonance Raman experiments have shown the origin of band-broadening of the lowest-energy absorption band in the absorption spectra of to be due to vibronic structure within one electronic transition.