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The recent emergence of a wide variety of two-dimensional (2D) materials has created new opportunities for device concepts and applications. In particular, the availability of semiconducting transition metal dichalcogenides, in addition to semi-metallic graphene and insulating boron nitride, has enabled the fabrication of all 2D van der Waals heterostructure devices. Furthermore, the concept of van der Waals heterostructures has the potential to be significantly broadened beyond layered solids. For example, molecular and polymeric organic solids, whose surface atoms possess saturated bonds, are also known to interact via van der Waals forces and thus offer an alternative for scalable integration with 2D materials. Here, we demonstrate the integration of an organic small molecule p-type semiconductor, pentacene, with a 2D n-type semiconductor, MoS2. The resulting p-n heterojunction is gate-tunable and shows asymmetric control over the anti-ambipolar transfer characteristic. In addition, the pentacene-MoS2 heterojunction exhibits a photovoltaic effect attributable to type II band alignment, which suggests that MoS2 can function as an acceptor in hybrid solar cells., Comment: 5 figures and supporting information. To appear in Nano Letters

The ligands 11-cyanodipyrido[3,2-a:2',3'-c]phenazine and 2-(11-dipyrido[3,2-a:2',3'-c]phenazine)-5-phenyl-1,3,4-oxadiazole have been coordinated to Re(I), Cu(I), Ru(II) and Ir(III) metal centres. Single-crystal X-ray analyses were performed on fac-chlorotricarbonyl(11-cyanodipyrido[3,2-a:2',3'-c]phenazine)rhenium (C(22)H(9)ClN(5)O(3)Re, a=6.509(5), b=12.403(5), c=13.907(5) A, alpha=96.88(5), beta=92.41(5), gamma=92.13(5) degrees , triclinic, P1, Z=2) and bis-2,2'-bipyridyl(2-(11-dipyrido[3,2-a:2',3'-c]phenazine)-5-phenyl-1,3,4-oxadiazole)ruthenium triflate2 CH(3)CN (C(52)H(36)F(6)N(12)O(8)RuS(2), a=10.601(5), b=12.420(5), c=20.066(5) A, alpha=92.846(5), beta=96.493(5), gamma=103.720(5) degrees , triclinic, P1, Z=2). The ground- and excited-state properties of the ligands and complexes have been investigated with a range of techniques, including electrochemistry, absorption and emission spectroscopy, spectroelectrochemistry and excited-state lifetime studies. Spectroscopic, time-resolved and DFT studies reveal that the ligand-centred (LC) transitions and their resultant excited states play an important role in the photophysical properties of the complexes. Evidence for the presence of lower-lying metal-to-ligand charge-transfer transitions is obtained from resonance Raman spectroscopy, but nanosecond transient Raman experiments suggest that once excited, the (3)LC state is populated.

Cu(I) complexes of the type [Cu(L)(PPh3)2]+, where L is the bidentate ligand 4,7-diphenyl-1, 10-phenanthroline (dip) and 3,4,7,8-tetramethyl-1,10-phenanthroline (tem) and their perdeuterated analogues, have been synthesised and the transient resonance Raman spectra of these complexes have been measured. The spectra show two sets of bands, one due to the PPh3 ligands and the other due to L.− created through the metal-to-ligand charge transfer transition. Density functional theory calculations have been used to model ligands and complexes in the ground state and good agreement has been found between calculated and measured bands with a mean absolute deviation of 8–10 cm−1 for the ligands and 5 cm−1 for the complexes. Shifts in the bands due to deuteration have also been well predicted, with the shifts for most modes predicted to within 10 cm−1. The structure and spectra of the excited states have been modelled using two approaches. The reduced state [Cu(L.−)(PH3)2] was used for both complexes to predict the changes in the structure of the polypyridyl ligand and for [Cu(dip)(PPh3)2]+ the triplet state was also optimised. Both approaches show that similar structural changes in the ligand are predicted. In the case of [Cu(dip)(PPh3)2]+* and [Cu(dip.−)(PPh3)2], the calculated states are 3A2 and 2A2, respectively, consistent with experiment. Calculations on [Cu(tem)(PPh3)2]+* give a 3B1 state. This is not consistent with experimental results. For [Cu(tem.−)(PPh3)2] both the 2B1 and 2A2 states may be calculated and the experimental spectrum of [Cu(tem)(PPh3)2]+* is closer to that of the 2A2 [Cu(tem.−)(PPh3)2] species. Calculated wavenumbers are compared to measured transient resonance Raman L.− bands and found to have a mean absolute deviation of 8 cm−1 for the triplet state of [Cu(dip)(PPh3)2]+ and 16 cm−1 for the reduced state of [Cu(tem)(PPh3)2]+. Copyright © 2008 John Wiley & Sons, Ltd.

The synthesis is described for a series of five molecular dyads comprising pyrene-based terminals covalently linked through a 1,3-disubstituted phenylene spacer. The extent of through-space communication between the pyrene units is modulated by steric interactions imposed by bulky moieties attached at the 6,8-positions of each pyrene unit. For the control compound, only hydrogen atoms occupy the 6,8 positions (DPI), whereas the remaining compounds incorporate ethynylene groups terminated with either triisopropylsilyl (DP2), 1-tert-butylbenzene (DP3), 2,6-di-tert-butylbenzene (DP4) or 1 -tert-butyl-3,5-dimethylbenzene (DP5) units. Each compound shows a mixture of monomer and excimer fluorescence in fluid solution at room temperature, but only monomer emission in a glassy matrix at 77 K. The ratio of monomer to excimer fluorescence depends markedly on the molecular structure; DPI is heavily biased in favour of the excimer and DP4 is enriched with monomer fluorescence. Photophysical properties, including laser induced and delayed fluorescence data, are reported for each compound. Delayed fluorescence occurs by both intramolecular and bimolecular steps, but these events take place on different timescales. The possibility is raised for using intramolecular triplet-triplet annihilation as a means of molecular imaging.

The thickness-dependent band structure of MoS2 implies that discontinuities in energy bands exist at the interface of monolayer (1L) and multilayer (ML) thin films. The characteristics of such heterojunctions are analyzed here using current versus voltage measurements, scanning photocurrent microscopy, and finite element simulations of charge carrier transport. Rectifying I-V curves are consistently observed between contacts on opposite sides of 1L/ML junctions, and a strong bias-dependent photocurrent is observed at the junction. Finite element device simulations with varying carrier concentrations and electron affinities show that a type II band alignment at single layer/multilayer junctions reproduces both the rectifying electrical characteristics and the photocurrent response under bias. However, the zero-bias junction photocurrent and its energy dependence are not explained by conventional photovoltaic and photothermoelectric mechanisms, indicating the contributions of hot carriers.

The thickness-dependent band structure of MoS2 implies that discontinuities in energy bands exist at the interface of monolayer (1L) and multilayer (ML) thin films. The characteristics of such heterojunctions are analyzed here using current versus voltage measurements, scanning photocurrent microscopy, and finite element simulations of charge carrier transport. Rectifying I-V curves are consistently observed between contacts on opposite sides of 1L-ML junctions, and a strong bias-dependent photocurrent is observed at the junction. Finite element device simulations with varying carrier concentrations and electron affinities show that a type II band alignment at single layer/multi-layer junctions reproduces both the rectifying electrical characteristics and the photocurrent response under bias. However, the zero-bias junction photocurrent and its energy dependence are not explained by conventional photovoltaic and photothermoelectric mechanisms, indicating the contributions of hot carriers., Comment: 5 figures plus supplement

Mono- and binuclear complexes of (Re(CO)3Cl) with dipyrido[2,3-a:3',2'-c]-6,7-dimethylphenazine (ppbMe2) were synthesised and their photophysical properties probed using picosecond time-resolved infrared spectroscopy (TRIR). Excitation of these complexes in solution at 400 nm produces short-lived excited states. The IR spectrum of the excited state of the mononuclear [Re(CO)3Cl(ppbMe2)] have nu(CO) bands shifted to higher wavenumber relative to those of the ground state. This is consistent with formation of a (3)MLCT excited state. The IR spectrum of the excited state of the bimetallic [(Re(CO)3Cl)2(micro-ppbMe2)] shows the formation of two distinct groups of nu(CO) bands. This is interpreted as the formation of two distinct Re sites arising from a localised MLCT state with formally oxidised Re centre and a formally reduced bridging ligand. The nu(CO) bands of the adjacent Re centre are affected by the reduction of the bridging ligand. On the IR timescale the excited state structure is best formulated as [Cl(CO)3Re(II)(micro-ppbMe2 *-)Re(I)(CO)3Cl].

The structural changes that occur when [Cu(pqx)(PPh(3))(2)](+) (pqx is 2-(2'-pyridyl)quinoxaline) undergoes excitation through a metal-to-ligand charge-transfer (MLCT) transition are investigated using resonance Raman excitation profiles coupled with density functional theory (DFT). The DFT calculations predict bond lengths to within 3 pm and absolute deviations of 7 cm(-1) for the vibrational frequencies of [Cu(pqx)(PPh(3))(2)](+). TD-DFT calculations of oscillator strengths (f = 0.089) and band positions (419 nm) showed close agreement with experiment (f = 0.07, 431 nm). Resonance Raman spectra show the 527 cm(-1) (nu(29)) and 1476 cm(-1) (nu(75)) modes undergo the largest dimensionless displacement (Delta = 1.5 and 1.1, respectively) following photoexcitation into the MLCT Franck-Condon region. The solvent couples strongly to the MLCT transition and resonance Raman intensity analysis (RRIA) gives a solvent reorganization energy of 3400 cm(-1) for dichloromethane and 2800 cm(-1) for chloroform solutions. A large inner-sphere reorganization of 3430 cm(-1) in dichloromethane solution (3520 cm(-1) in chloroform solution) was found for [Cu(pqx)(PPh(3))(2)](+), indicating that the molecule as a whole undergoes significant distortion following MLCT excitation.

The ligands 11-bromodipyrido[3,2-a:2',3'-c]phenazine and ethyl dipyrido[3,2-a:2',3'-c]phenazine-11-carboxylate have been prepared and coordinated to ruthenium(II), rhenium(I), and copper(I) metal centers. The electronic effects of substitution of dipyrido[2,3-a:3',2'-c]phenazine (dppz) have been investigated by spectroscopy and electrochemistry, and some photophysical properties have been studied. The crystal structures of [Re(L)(CO)(3)Cl] (L = ethyl dipyrido[3,2-a:2',3'-c]phenazine-11-carboxylate or 11-bromodipyrido[3,2-a:2',3'-c]phenazine) are presented. Density functional theory calculations on the complexes show only small deviations in bond lengths and angles (most bonds within 0.02 Angstroms, most angles within 2 degrees) from the crystallographic data. Furthermore, the vibrational spectra of the strongest Raman and IR bands are predicted to within an average 6 cm(-1) for the complexes [Re(L)(CO)(3)Cl] and [Cu(L)(triphenylphosphine)(2)]BF(4) (in the 1000-1700 cm(-1) region). Spectroscopic and electrochemical evidence suggest that reduction of the complex causes structural changes across the entire dppz ligand. This is unusual as dppz-based ligands typically have electrochemical properties that suggest charge localization with reduction on the phenazine portion of the ligand. The excited-state lifetimes of the complexes have been measured, and they range from ca. 200 ns for the [Ru(L)(2,2'-bipyridine)(2)](PF(6))(2) complexes to over 2 mus for [Cu(11-bromodipyrido[3,2-a:2',3'-c]phenazine)(PPh(3))(2)](BF(4)) at room temperature. The emission spectra suggest that the unusually long-lived excited states of the copper complexes result from metal-to-ligand charge transfer (MLCT) transitions as they are completely quenched in methanol. Electroluminescent films may be fabricated from these compounds; they show MLCT state emission even at low doping levels [0.1% by weight in poly(vinylcarbazole) polymer matrix].

An improved method for the synthesis of the polypyridyl ligand [2,3-a:3′,2′-c]dipyridophenazine (ppb) is reported. In addition, the syntheses of the new ppb-based ligands L (L=[2,3-a:3′,2′-c]dipyridophenazine, [2,3-a:3′,2′-c]dipyrido-6,7-dimethylphenazine, [2,3-a:3′,2′-c]dipyrido-6,7-dichlorophenazine, [2,3-a:3′,2′-c]dipyrido[1,2-e]benzophenazine, [2,3-a:3′,2′-c:3″,2″-e]tripyridoquinoxaline and [2,3-a:3′,2′-c]dipyrido-5-methylphenazine) are detailed. The complexes [Os(ppb)(bpy)2]2+ and [Os(L)(bpy)2]2+ have been synthesised and their electrochemical, electronic absorption and UV–Vis spectrochemical properties measured. Syntheses of the rhenium(I) complexes fac-[Re(L″)(CO)3Cl] (L″ = [2,3-a:3′,2′-c]dipyridophenazine, [2,3-a:3′,2′-c]dipyrido-6,7-dimethylphenazine, [2,3-a:3′,2′-c]dipyrido-6,7-dichlorophenazine, [2,3-a:3′,2′-c]dipyrido[1,2-e]benzophenazine) are also reported. The osmium(II) complexes [Os(L′)(bpy)2]2+ (L′ = 2,3-di-(2-pyridyl)quinoxaline, 6,7-dimethyl-2,3-di-(2-pyridyl)quinoxaline, 6,7-chloro-2,3-di-(2-pyridyl)quinoxaline, 2,3-di-(2-pyridyl)benzo[g]quinoxaline, 4-methyl-di-(2-pyridyl)quinoxaline) have also been prepared and studied. The electronic spectra of the Os and Re complexes are dominated by strong MLCT transitions. The lowest energy MLCT transitions correlate linearly with the first reduction potential for the [Os(L)(bpy)2]2+ series. Electrochemical oxidation of the [Os(L)(bpy)2]2+ and [Os(L′)(bpy)2]2+ complexes results in the appearance of LMCT transitions in the visible region while reduction of the [Os(L)(bpy)2]2+ complexes produces complex electronic spectra. Comparison with the reduced fac-[Re(L″)(CO)3Cl] complexes allows assignment of L″ − π→π* transitions in the NIR (1200–1000 nm) and red (850–700 nm) regions. The nonsymmetrical ligands [2,3-a:3′,2′-c:3″,2″-e]tripyridoquinoxaline and [2,3-a:3′,2′-c]dipyrido-5-methylphenazine both coordinate to the [Os(bpy)2]2+ unit in a stereospecific manner to give a single geometric isomer. The crystal structure of [Re(CO)3(ppb)Cl] is reported, in which the polypyridyl ligand deviates significantly from planarity.

The drug carbamazepine has been modeled, using ab initio density functional theory calculations [B3LYP/6–31G(d)], both as a single molecule and as a dimer. The predicted geometry of the single molecule calculation is compared with the crystallographic data on each of the polymorphs (carbamazepine forms I and III). From the predicted geometry it is possible to calculate the IR and Raman spectra; these predictions compare favorably with the observed spectra of both polymorphs of carbamazepine for most of the bands. The spectral differences between the polymorphs are more striking in the IR than the Raman spectra, with strong IR bands at 1688 and 1396 cm−1 in form I shifting to 1678 and 1388 cm−1 in form III. Analysis of the potential energy distributions for the calculated normal modes reveals that the vibrations are localized across different ring systems of the carbamazepine structure. Most notably, the polymorph-sensitive modes in the IR spectra are localized to the pendant CONH2 group; it is these modes that show the greatest disparity from the calculated spectra, and it is this group that is perturbed in the polymorph crystal structures. The calculated dimer structure is similar to that of the single molecule, but the polymorph-sensitive IR modes are significantly better predicted by the dimer calculation. Copyright © 2004 John Wiley & Sons, Ltd.

The vibrational spectra (Raman and IR) of 1,10-phenanthroline (phen), its perdeuterated analogue (d8-1,10-phenanthroline, d8-phen), and the copper(I) complexes [Cu(phen)(PPh3)2]+ and [Cu(d8-phen)(PPh3)2]+ have been measured. These spectra may be modeled using DFT calculations (B3LYP/6-31G(d)). The calculated structure compares favorably with crystallographic data. The time-resolved resonance Raman spectra of the copper(I) complexes were used to provide spectral signatures of phen• - and d8-phen• -. Geometries and vibrational spectra of the radical anions may be calculated in two ways: first as phen• -, which has been previously shown to be a 2B1 state. Calculations with B3LYP require the 6-311+G(d,p) basis set in order to predict this state correctly for the radical anion, rather than the close-lying 2A2 state, therefore giving a reasonable prediction of the geometry and spectra. Second, using [Cu(phen• -)(PH3)2] it is possible to model the radical anion at the B3LYP/6-31G(d) level because the metal cent...

We present an analysis of the resonance Raman intensities of an intramolecular charge-transfer transition using a time-domain formulation of the Raman scattering process. This analysis provides mode-specific reorganization energies for the vibrational modes that couple to the photoinduced charge-transfer event. In addition, the absolute magnitude of the resonance Raman intensities allows the surrounding solvent contribution to the reorganization energy to also be determined. The analysis demonstrates that for the intramolecular charge-transfer considered here the solvent reorganization is of a similar magnitude to the combined intramolecular reorganization energies.

GaN–InGaN core–shell nanowire array devices are characterized by spectrally resolved scanning photocurrent microscopy (SPCM). The spatially resolved external quantum efficiency is correlated with structure and composition inferred from atomic force microscope (AFM) topography, scanning transmission electron microscope (STEM) imaging, Raman microspectroscopy, and scanning photocurrent microscopy (SPCM) maps of the effective absorption edge. The experimental analyses are coupled with finite difference time domain simulations to provide mechanistic understanding of spatial variations in carrier generation and collection, which is essential to the development of heterogeneous novel architecture solar cell devices.

A resonance Raman intensity analysis of the metal-to-ligand charge-transfer (MLCT) transition for the rhenium compound Re(2-(2'-pyridyl)quinoxaline)(CO)(3)Cl (RePQX) is presented. Photoinduced geometry changes are calculated, and the results are presented using the vibrational normal modes and the redundant internal coordinates. A density functional theory calculation is used to determine the ground-state nonresonant Raman spectrum and a transformation matrix that transforms the redundant internal coordinates into the normal modes. The normal modes nu(37) (rhenium coordination sphere distortion) and nu(75) (ligand skeletal stretch) show the largest photoinduced geometry change (Delta = 1.0 and 0.7, respectively). A single carbonyl mode is enhanced in the resonance Raman spectra. Time-dependent density functional theory is used to calculate excited-state geometry changes, which are subsequently used to determine the signs of the photoinduced normal mode displacements. Transforming to internal coordinates reveals that all the CO bond lengths are displaced in the excited state. The Re-C and C-C ligand bond lengths are also displaced in the excited state. The results are discussed in terms of a simple one-electron picture for the electronic transition. Many bond angles and torsional coordinates are also displaced by the metal-to-ligand charge transfer, and most of these are associated with the rhenium coordination sphere. It is demonstrated that using internal coordinates presents a clear picture of the geometry changes associated with photoinduced electron transfer in metal polypyridyl systems.

A molecular dyad has been synthesized in which the main chromophore is a 1,4-diethynylated benzene residue terminated with pyrene moieties, this latter unit acting as a single chromophore. A spiropyran group has been condensed to the central phenylene ring so as to position a weak electron donor close to the pyrene unit. Illumination of the pyrene-based chromophore leads to formation of a fluorescent exciplex in polar solvents but pyrene-like fluorescence is observed in nonpolar solvents. The exciplex has a lifetime of a few nanoseconds and undergoes intersystem crossing to the pyrene-like triplet state with low efficiency. Attaching a 4-nitrobenzene group to the open end of the spiropyran unit creates a new route for decay of the exciplex whereby the triplet state of the spiropyran is formed. Nonradiative decay of this latter species results in ring opening to form the corresponding merocyanine species. Rate constants for the various steps have been obtained from time-resolved fluorescence spectroscopy carried out over a modest temperature range. Under visible light illumination, the merocyanine form reverts to the original spiropyran geometry so that the cycle is closed. Energy transfer from the pyrene chromophore to the merocyanine unit leads to an increased rate of ring closure and serves to push the steady-state composition in favor of the spiropyran form.

The lowest energy transition of [Ru(CN)(4)(ppb)](2-) (ppb = dipyrido[2,3-a:3',2'-c]phenazine), a metal-to-ligand charge transfer, has been probed using resonance Raman spectroscopy with excitation wavelengths (488, 514, 530, and 568 nm) spanning the lowest energy absorption band centered at 522 nm. Wave packet modeling was used to simultaneously model this lowest energy absorption band and the cross sections of the resonance Raman bands at the series of excitation wavelengths across this absorption band. A fit to within +/-20% was obtained for the Raman cross sections, close to the experimental uncertainty which is typically 10-20%. Delta values of 0.1-0.4 were obtained for modes which were either localized on the ppb ligand (345-1599 cm(-1)) or the CN modes (2063 and 2097 cm(-1)). DFT calculations reveal that the resonance Raman bands observed are due to modes delocalized over the entire ppb ligand.

A number of rhenium complexes with binaphthyridine and biquinoline ligands have been synthesized and studied. These are [Re(L)(CO)3Cl] where L = 3,3'-dimethylene-2,2'-bi-1,8-naphthyridine (dbn), 2,2'-bi-1,8-naphthyridine (bn), 3,3'-dimethylene-2,2'-biquinoline (dbq), and 3,3'-dimethyl-2,2'-biquinoline (diq). This series represents ligands in which the electronic properties and steric preferences are tuned. These complexes are modeled using density functional theory (DFT). An analysis of the resonance Raman spectra for these complexes, in concert with the vibrational assignments, reveals that the accepting molecular orbital (MO) in the metal-to-ligand charge transfer (MLCT) transition is the LUMO and causes bonding changes at the inter-ring section of the ligand. The electronic absorption spectroelectrochemistry for the reduced complexes of [Re(dbn)(CO)3Cl], [Re(dbq)(CO)3Cl], and [Re(diq)(CO)3Cl] suggest that the singly occupied MO is delocalized over the entire ligand structure despite the nonplanar nature of the diq ligand in [Re(diq)(CO)3Cl]. The IR spectroelectrochemistry for [Re(dbn)(CO)3Cl], [Re(dbq)(CO)3Cl], and [Re(bn)(CO)3Cl] reveal that reduction lowers the CO ligand vibrational frequencies to a similar extent in all three complexes. The substitution of naphthyridine for quinoline has little effect on the nature of the singly occupied MO. These data are supported by DFT calculations on the reduced complexes, which reveal that the ligands are flattened out by reduction: This may explain the similarity in the properties of the reduced complexes.

The lifetimes and transient resonance Raman spectra for Ru(II) complexes with the dipyrido[2,3-a:3',2'-c]phenazine (ppb) ligand and substituted analogues have been measured. The effect of altering the Ru(II) center ([Ru(CN)4]2- versus [Ru(bpy)2]2+), of the complex, on the excited-state lifetimes and spectra has been considered. For [Ru(bpy)2L]2+ complexes the excited-state lifetimes range from 124 to 600 ns in MeCN depending on the substituents on the ppb ligand. For the [Ru(CN)4L]2- complexes the lifetimes in H2O are approximately 5 ns. The transient resonance Raman spectra for the MLCT excited states of these complexes have been measured. The data are analyzed by comparison with the resonance Raman spectra of the electrochemically reduced [(PPh3)2Cu(mu-L*-)Cu(PPh3)2]+ complexes. The vibrational spectra of the complexes have been modeled using DFT methods. For experimental ground-state vibrational spectra of the complexes the data may be compared to calculated spectra of the ligand or metal complex. It is found that the mean absolute deviation between experimental and calculated frequencies is less for the calculation on the respective metal complexes than for the ligand. For the transient resonance Raman spectra of the complexes the observed vibrational bands may be compared with those of the calculated ligand radical anion, the reduced complex [Ru(CN)4L*-]3-, or the triplet state of the complex. In terms of a correlation with the observed transient RR spectra, calculations on the metal complex models offered no significant improvement compared to those based on the ligand radical anion alone. In all cases small structural changes are predicted on going from the ground to excited state.

A series of bridging ligands, dipyrido[2,3-a:3',2'-c]phenazine (ppb), dipyrido[2,3-a:3',2'-c]-6,7-dichlorophenazine (ppbCl2), and dipyrido[2,3-a:3',2'-c]-6,7-dimethylphenazine (ppbMe2), and their binuclear copper(I) complexes have been synthesized, and their spectral properties were measured. The single-crystal structure of the complex, [(PPh3)2Cu(mu-ppbCl2)Cu(PPh3)2](BF4)2 in the monoclinic space group P21/c, 18.2590(1), 21.1833(3), 23.2960(3) A with Z = 4 is reported. The copper(I) complexes are deeply colored through MLCT transitions in the visible region. The vibrational spectra of the ligands have been modeled using ab initio hybrid density functional theory (DFT) methods (B3LYP/6-31G(d)) and compared to experimental FT-Raman and IR data. The DFT calculations are used to interpret the resonance Raman spectra, and thus the electronic spectra, of the complexes. The preferential enhancement of modes associated with the phenanthroline section of the ligands with blue excitation (lambda(exc) = 457.9 nm) over phenazine-based modes with redder excitation (lambda(exc) = 514.5 and 632.8 nm) suggests the 2 MLCT transitions terminated on different unoccupied MOs are present under the visible absorption envelope. The radical anion species of the ligands are prepared by the electrochemical reduction of the binuclear copper(I) complexes; no evidence of dechelation prevalent in other copper(I) complexes is observed. The resonance Raman spectra of the reduced complexes are dramatically different from those of the parent species. Across the series common bands are observed at about 1590 and 1570 cm(-1) which do not shift with reduction but are altered in intensity. The normal-mode analysis of the radical anion species suggests that these normal modes primarily involve bond length distortions that are unaffected by reduction.