Homoleptic Bis Research Articles

Voltage clustering in redox-active ligand complexes: mitigating electronic communication through choice of metal ion.

The redox-active bis(imino)acenapthene (BIAN) ligand was used to synthesize homoleptic aluminum, chromium, and gallium complexes of the general formula (BIAN)3M. The resulting compounds were characterized using X-ray crystallography, NMR, EPR, magnetic susceptibility and cyclic voltammetry measurements and modeled using both DFT and ab initio wavefunction calculations to compare the orbital contributions of main group elements and transition metals in ligand-based redox events. Complexes of this type have the potential to improve the energy density and electrolyte stability of grid-scale energy storage technologies, such as redox flow batteries, through thermodynamically-clustered redox events.

Targeting of DNA molecules, BSA/c-Met tyrosine kinase receptors and anti-proliferative activity of bis(terpyridine)copper(ii) complexes.

A series of homoleptic bis(terpyridine)copper(ii) complexes of the type [Cu(L(1-5))2]Cl2 (), where L(1-5) = 4'-(4-substituted)-2,2':6',2''-terpyridines, have been synthesized and characterized. The molecular structure of complex was confirmed by the single crystal XRD technique, and the geometry of the complexes is best described as distorted octahedral. Structural parameters from the crystallographic and DFT studies are in good agreement with each other. The small HOMO-LUMO energy gap supports bioefficacy of the complexes. DNA binding studies show high intrinsic binding constant values 1.53 ± 0.15, 1.62 ± 0.08 and 3.09 ± 0.12 × 10(5) M(-1) for complexes , and , respectively, with intercalative mode of binding to CT-DNA. The binding results were further supported by molecular docking studies. The experimental results indicate that the interaction between the complexes and BSA protein involves a static quenching mechanism. The molecular docking studies with c-Met tyrosine kinase receptors show hydrophobic and π-π interactions. All the complexes bring about hydroxyl radical mediated DNA cleavage in the presence of H2O2. In vitro cytotoxicities of the complexes () were tested against three cancerous cell lines, namely human breast adenocarcinoma (MCF-7), epithelioma (Hep-2) and cervical (HeLa) cell lines, and one non-tumorigenic human dermal fibroblast (NHDF) cell line by MTT reduction assay. The morphological assessment data obtained using Hoechst 33258 staining revealed that complex induces apoptosis much more effectively than the other complexes.

A series of homoleptic bis(phthalocyaninato) rare earth sandwich complexes with large two-photon absorption cross-section

The third-order nonlinear optical properties of a series of homoleptic substituted phthalocyaninato rare earth double-decker complexes were experimentally investigated by the Z-scan technique at the wavelength of 800 nm. All complexes were revealed to exhibit large two-photon absorption cross-sections. The measured two-photon absorption values of these complexes remain constant at different laser intensities, indicating nonlinearity is originated from pure two-photon absorption behavior. In addition, the two-photon absorption cross-section of these complexes increases along with the decrease of the rare earth atomic radius, suggesting that intense intramolecular π–π interaction between the phthalocyaninato macrocycles improves the third-order nonlinear optical properties. The optical limiting behavior of these complexes in chloroform was also investigated by using femtosecond laser pulses. The excellent two-photon absorption properties and optical limiting performance indicate their good application potential in photonic and optoelectronic devices.

Structures and bonding of homoleptic bis(2,3-dihydro-1,3-diborole) complexes of nickel and platinum

Homoleptic metal complexes of the boron heterocycle 2,3-dihydro-1,3-diborole {(R1C)2(R2B)2R3(H)C} 1 are described. X-Ray crystal structure determinations of two nickel and platinum derivatives are presented. In the nickel complex [Ni(1d)2] 6d (R1 = R2 = R3 = Et) the essentially coplanar heterocycles attain a pentahapto coordination mode with a gauche orientation with respect to one another. An 18 VE count is attained. In contrast, in the 14 VE platinum complex [Pt(1a)2] 4a (R1 = R2 = Et, R3 = Me) the ligands are strongly folded and adopt a tetrahapto coordination. The molecule is centrosymmetric in the crystalline state. DFT MO calculations are presented to establish the relative stabilities of these coordination modes for nickel and platinum, respectively.

Coordination of β-Ketoimine-Derived Ligands at Main Group and Transition Metals

The β-ketoimine HC[MeC(O)][MeC(NHt-Bu)] (1H) (Me = methyl) was used as a ligand in the synthesis of organo-aluminium and gallium compounds. With Al, the NH functionality was deprotonated to form the N,O-chelating β-ketoiminate ligand in Al{HC[MeC(O)][MeC(Nt-Bu)]}Me2 (3) (t-Bu = tertiary butyl), whereas the neutral form coordinated to trimethylgallium via the oxygen atom to form the adduct GaMe3·{HC[MeC(O)][MeC(NHt-Bu)]} (4). Reaction of 1H with Ar†NH2 (Ar† = 2-t-BuC6H4) afforded the new N-aryl β-ketoimine HC[MeC(O)][MeC(NHAr†)] (2H), which reacted with Pd(OAc)2 (OAc = acetate = CH3CO2–) to afford the heteroleptic dimer {Pd[HC(MeC(O))(MeC(NAr†))](μ-OAc)}2 ([5]2). The homoleptic bis(β-ketoiminate) Pd{HC[MeC(O)][MeC(NAr†)]}2 (6) was isolated as a minor product of this reaction. The crystal structures of compounds 3, 4, [5]2, and 6 are reported.

Kinetic model and mechanism of the acid dissociation of d-metal bis(dipyrrolylmethenates)

A kinetic model and a mechanism have been developed by quantum chemical simulation for the protolytic dissociation of dinuclear homoleptic bis(dipyrrolylmethenates) of d-metals (M) with the general formula [M2L2] and a double-helix structure. The reaction is described by a third-order equation that is first-order with respect to the complex and second-order with respect to the acid. The main contribution to the total dissociation rate is made by the rate-determining step, specifically, attack of the second acetic acid molecule on the nitrogen atom of one of the coordination sites of the helicate. The dinuclear helicates of 3,3′-bis(dipyrrolylmethenes) are more inert in an acidic medium than 2,3′- and 2,2′-bis(dipyrrolylmethenes).

Constructing bis(porphyrinato) rare earth double-decker complexes involving N-confused porphyrin.

Reaction of metal-free N-confused 5,10,15,20-tetrakis(4-chlorophenyl)porphyrin (H2NTClPP) with metal-free 5,10,15,20-tetrakis[(4-tert-butyl)phenyl]porphyrin (H2TBPP) in the presence of M(III)(acac)3·nH2O (acac = acetylacetonate) in refluxing 1,2,4-trichlorobenzene (TCB) led to the isolation of heteroleptic bis(porphyrinato) rare earth compounds M(III)(HNTClPP)(TBPP) (M = La, Pr) (1, 2) in 6.7-10% yield. These represent the first examples of sandwich-type porphyrin rare earth double-decker complexes that involve N-confused porphyrin ligand. Different from their homoleptic bis(porphyrinato) rare earth double-decker counterparts HM(III)(TBPP)2 (M = La, Pr) (3, 4), the acidic proton in the heteroleptic analogues was revealed to localize at the inverted pyrrole nitrogen atom of the N-confused porphyrin ligand on the basis of NMR spectroscopic studies. Nevertheless, their heteroleptic bis(porphyrinato) sandwich molecular nature was confirmed on the basis of single crystal X-ray diffraction analysis over the praseodymium double-decker complex.

Bis[octakis(2,6-dimethylphenoxy)phthalocyaninato] rare earth(III) complexes: Structure, spectroscopic, and electrochemical properties

Homoleptic bis(phthalocyaninato) rare earth complexes MIII[Pc(β-DMPO)8]2 [Pc(β-DMPO)8 = 2, 3, 9, 10, 16, 17, 23, 24-octakis(2,6-dimethylphenoxy) phthalocyaninate; M = Pr, Nd and Sm] have been synthesized and characterized by a series of spectroscopic methods including matrix-assisted laser desorption/ionization time of flight mass spectrometry, nuclear magnetic resonance spectrum, electronic absorption and infrared spectroscopy. Their molecular structures have been determined by single crystal X-ray diffraction analysis and electrochemical properties studied by cyclic voltammetry. The electrochemical studies illuminate the electron-withdrawing nature of these substituents in the double-deckers. Density functional theory (DFT) calculations are carried out to further clarify the electron transition nature and orbital information. Based on the structural, spectroscopic, electrochemical and theoretical studies, we found that the substitution effect as well as the size of the metal centers altered the molecular and electronic structures significantly.

Catalytic and Stoichiometric Cumulene Formation within Dimeric Group 2 Acetylides

A series of β-diketiminate-supported magnesium and calcium acetylide complexes have been synthesized by σ-bond metathesis of magnesium n-butyl or magnesium and calcium amido precursors and a range of terminal acetylenes. The dimeric complexes have been characterized by NMR spectroscopy and X-ray diffraction analysis. The homoleptic bis(amido) and dialkyl complexes [M{X(SiMe3)2}2(THF)2] (M = Ca, Sr; X = N, CH) have been assessed for the atom-efficient, catalytic head-to-head dimerization of donor-functionalized terminal alkynes into butatrienes and aryl-/silyl-substituted terminal acetylenes into 1,3-enynes. Deuterium labeling studies of the catalytic reactions are suggested to imply that triene formation requires concerted proton delivery and rearrangement via an adjacent methylene group at a bimetallic alkaline-earth species.

Tuning the Electronics of Bis(tridentate)ruthenium(II) Complexes with Long-Lived Excited States: Modifications to the Ligand Skeleton beyond Classical Electron Donor or Electron Withdrawing Group Decorations

A series of homoleptic bis(tridentate) [Ru(L)2](2+) (1, 3) and heteroleptic [Ru(L)(dqp)](2+) complexes (2, 4) [L = dqxp (1, 2) or dNinp (3, 4); dqxp = 2,6-di(quinoxalin-5-yl)pyridine, dNinp = 2,6-di(N-7-azaindol-1-yl)pyridine, dqp = 2,6-di(quinolin-8-yl)pyridine] was prepared and in the case of 2 and 4 structurally characterized. The presence of dqxp and dNinp in 1-4 result in anodically shifted oxidation potentials of the Ru(3+/2+) couple compared to that of the archetypical [Ru(dqp)2](2+) (5), most pronounced for [Ru(dqxp)2](2+) (1) with a shift of +470 mV. These experimental findings are corroborated by DFT calculations, which show contributions to the complexes' HOMOs by the polypyridine ligands, thereby stabilizing the HOMOs and impeding electron extraction. Complex 3 exhibits an unusual electronic absorption spectrum with its lowest energy maximum at 382 nm. TD-DFT calculations suggest that this high-energy transition is caused by a localization of the LUMO on the central pyridine fragments of the dNinp ligands in 3, leaving the lateral azaindole units merely spectator fragments. The opposite is the case in 1, where the LUMO experiences large stabilization by the lateral quinoxalines. Owing to the differences in LUMO energies, the complexes' reduction potentials differ by about 900 mV [E(1/2)(1(2+/1+)) = -1.17 V, E(c,p)(3(2+/1+)) = -2.06 V vs Fc(+/0)]. As complexes 1-4 exhibit similar excited state energies of around 1.80 V, the variations of the lateral heterocycles allow the tuning of the complexes' excited state oxidation strengths over a range of 900 mV. Complex 1 is the strongest excited state oxidant of the series, exceeding even [Ru(bpy)3](2+) by more than 200 mV. At room temperature, complex 3 is nonemissive, whereas complexes 1, 2, and 4 exhibit excited state lifetimes of 255, 120, and 1570 ns, respectively. The excited state lifetimes are thus somewhat shortened compared to that of 5 (3000 ns) but still acceptable to qualify the complexes as photosensitizers in light-induced charge-transfer schemes, especially for those that require high oxidative power.

Coordination Programming of Photofunctional Molecules

Our recent achievements relating to photofunctional molecules are addressed. Section 1 discloses a new concept of photoisomerization. Pyridylpyrimidine-copper complexes undergo a ring inversion that can be modulated by the redox state of the copper center. In combination with an intermolecular photoelectron transfer (PET) initiated by the metal-to-ligand charge transfer (MLCT) transition of the Cu(I) state, we realize photonic regulation of the ring inversion. Section 2 reports on the first examples of heteroleptic bis(dipyrrinato)zinc(II) complexes. Conventional homoleptic bis(dipyrrinato)zinc(II) complexes suffered from low fluorescence quantum yields, whereas the heteroleptic ones feature bright fluorescence even in polar solvents. Section 3 describes our new findings on Pechmann dye, which was first synthesized in 1882. New synthetic procedures for Pechmann dye using dimethyl bis(arylethynyl)fumarate as a starting material gives rise to its new structural isomer. We also demonstrate potentiality of a donor-acceptor-donor type of Pechmann dye in organic electronics.

Homoleptic Bis(aryl)acenaphthenequinonediimine–CuI Complexes – Synthesis and Characterization of a Family of Compounds with Improved Light‐Gathering Characteristics

AbstractA group of bis(aryl)acenaphthenequinonediimine (Ar‐BIAN) ligands were synthesized through a modified procedure, which bypasses the need for absolutely dry conditions during the initial template synthesis. The molecular and electronic structure of the corresponding homoleptic [Cu(Ar‐BIAN)2]BF4 complexes were probed by means of a variety of spectroscopic methods. In accord with solution 13C NMR spectra, X‐ray crystallography reveals D2 or approximate D2 symmetry for the [Cu(p‐Cl‐BIAN)2]+ and [Cu(p‐Me‐BIAN)2]+ cations and noncrystallographic C2 symmetry for the [Cu(o‐Ph‐BIAN)2]+ cation. The structures of the p‐Cl‐, p‐Me, and o‐Ph‐BIAN complexes agree with the presence of ligands in their neutral form according to the lengths of the relevant C–C and C=N bonds of the organic skeleton. The concerted stereo–electronic effects of the substituents on the aryl rings affect the electron donor/acceptor capacities of the ligands and the structures of the complexes, as the study of the visible absorption spectra of the complexes indicates. The spectra of the complexes are dominated by intense and broad metal‐to‐ligand charge transfer (MLCT) bands that enter the near‐infrared (NIR) region. Additionally, electrochemical studies undertaken reveal several successive electron capture and release processes, which further manifest the redox versatility of the ligands.

A new type of sandwich compound: homoleptic bis(trimethylenemethane) complexes of the first row transition metals

The metal carbonyl complexes [η4-(CH2)3C]Fe(CO)3 and [η4-(CH2)3C]Cr(CO)4 have been synthesized containing the umbrella-shaped trimethylenemethane ligand. The prospect of using this ligand in the metal sandwich complexes [(CH2)3C]2M (M = Ti, V, Cr, Mn, Fe, Co, Ni) has now been investigated by density functional theory. The lowest energy structures of such complexes have the metal atom sandwiched between two tetrahapto trimethylenemethane ligands. Singlet spin state structures are strongly preferred for the titanium and nickel derivatives and doublet spin state structures for the vanadium and cobalt derivatives. Similarly, the triplet spin state is preferred for the iron derivative by more than 11 kcal mol−1. The preferred spin states for the chromium and manganese derivatives depend on the functional used for the structure optimization. Thus the B3LYP and B3LYP* methods predict the higher spin states, namely triplet for chromium and quartet for manganese. However, the BP86 method predicts the lower spin states of singlet for chromium and doublet for manganese. The higher spin state structures for the late transition metal derivatives, namely quintet [(CH2)3C]2Fe, quartet [(CH2)3C]2Co, and triplet [(CH2)3C]2Ni, have trihapto rather than tetrahapto trimethylenemethane ligands. The frontier molecular orbitals in the singlet [(CH2)3C]2M derivatives (M = Ti, Ni) suggest strong metal–ligand σ and π bonding but insignificant metal–ligand δ bonding.

Synthesis and Structures of Cuprous Triptycylthiolate Complexes

A synthesis of 1-(thioacetyl)triptycene (5), a convenient protected form of 1-(thiolato)triptycene [STrip](-), is described, a key transformation being the high yield conversion of tert-butyl 1-triptycenyl sulfide (8) to 5 by a protocol employing BBr(3)/AcCl. Syntheses of the two-coordinate copper(I) compounds [Bu(4)N][Cu(STrip)(2)], [Bu(4)N]10, and [(Cu(IMes)(STrip)] (13) proceed readily by chloride displacement from CuCl and [Cu(IMes)Cl], respectively. Reaction of 10 with Ph(3)SiSH or Me(3)SiI produces the heteroleptic species [Cu(STrip)(SSiPh(3))](-) (11) and [Cu(STrip)I](-) (12), detected by mass spectrometry, in mixture with the homoleptic bis(thiolate) anions. Structural identification by X-ray crystallography of the ligand precursor molecules 9-(thioacetyl)anthracene (4, triclinic and orthorhombic polymorphs), tert-butyl 9-anthracenyl sulfide (7), 5, and tert-butyl 1-triptycenyl sulfide (8) are presented. Crystallographic characterization of bis(9-anthracenyl)sulfide (3), which features a C-S-C angle of 104.0° and twist angle of 54.8° between anthracenyl planes, is also given. A crystal structure of [Bu(4)N][(STrip)], [Bu(4)N]9, provides an experimental measure of 144.6° for the ligand cone angle. The crystal structures of [Bu(4)N]10 and 13 are reported, the former of which reveals an unexpectedly small C-S···S-C torsion angle of ∼41° (average of two values), which confers a near "cis" disposition of the triptycenyl groups with respect the S-Cu-S axis. This conformation is governed by interligand π···π and CH···π interactions. A crystal structure of an adventitious product, [Bu(4)N][(Cu-STrip)(6)(μ(6)-Br)]·[Bu(4)N][PF(6)], [Bu(4)N]14·[Bu(4)N][PF(6)] is described, which reveals a cyclic hexameric structure previously unobserved in cuprous thiolate chemistry. The Cu(6)S(6) ring displays a centrosymmetric cyclohexane chair type conformation with a Br(-) ion residing at the inversion center and held in place by apparent soft-soft interactions with the Cu(I) ions.

Fluorescent azadipyrrinato zinc(ii) complex: hybridisation with a dipyrrinato ligand

We synthesised heteroleptic azadipyrrinato-dipyrrinato hybrid zinc(II) complex 1-Zn-2, by means of the stepwise coordination method. Homoleptic bis(azadipyrrinato)zinc(II) complex 1-Zn-1 was non-fluorescent, whereas 1-Zn-2 exhibited detectable fluorescence from azadipyrrinato ligand 1.

Tuning the semiconducting nature of bis(phthalocyaninato) holmium complexes via peripheral substituents

The semiconducting properties of the heteroleptic and homoleptic bis(phthalocyaninato) holmium complexes bearing electron-withdrawing phenoxy substituents at the phthalocyanine periphery, namely Ho(Pc)[Pc(OPh)8] (1) and Ho[Pc(OPh)8]2 (2) [Pc = unsubstituted phthalocyaninate; Pc(OPh)8 = 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninate] have been investigated comparatively. Using a solution-based Quasi–Langmuir–Shafer (QLS) method, the thin solid films of the two compounds were fabricated. The structure and properties of the thin films were investigated by UV-vis absorption spectra, X-ray diffraction (XRD) and atomic force microscopy (AFM). Experimental results indicated that H-type molecular stacking mode with the common preferential molecular “edge-on” orientation relative to the substrate has been formed, and the intermolecular face-to-face π–π interaction and film microstructures are effectively improve by increasing the number of phenoxy substituents of the Pc periphery within the double-decker complexes. The electrical conductivity of Ho(Pc)[Pc(OPh)8] films was measured to be approximately 4 orders of magnitude larger than that of Ho[Pc(OPh)8]2 films, indicating significant effect of peripheral electron-withdrawing phenoxy groups on conducting behaviour of bis(phthalocyaninato) holmium complexes. In addition, the gas sensing behaviour of the QLS films of 1 and 2 toward electron donating gas, NH3, was investigated in the concentration range of 15–800 ppm. Surprisingly, contrary responses towards NH3 were found for the QLS films of 1 and 2. In the presence of NH3, the conductivity of the films of Ho(Pc)[Pc(OPh)8] (1) decreased while the conductivity of the films of Ho[Pc(OPh)8]2 (2) increased. This observation clearly demonstrated the p- and n-type semiconducting nature for 1 and 2, respectively. Furthermore, compared to the heteroleptic 1 having a hole mobility of 1.7 × 10−4 cm2 V−1 s−1, homoleptic 2 exhibits an electron mobility as high as 0.54 cm2 V−1 s−1. Therefore, the inversion of the semiconducting nature of the double-deckers from p- to n-type can be successfully and easily realized just by increasing the number of peripheral phenoxy groups attached to the conjugated Pc cores.

Bis-diimidazolylidine complexes of nickel: Investigations into nickel catalyzed coupling reactions

Air and moisture stable homoleptic bis(diimidazolylidine)nickel(II) complexes, ([(diNHC)(2)Ni](2+)) 3a,b and their corresponding silver(I) 4a,b and palladium(II) 5a,b complexes were synthesized and characterized by NMR and single crystal X-ray analysis. The catalytic potential of complex 3a was assessed in Mizoroki-Heck and Suzuki-Miyaura coupling reactions. In the Suzuki-Miyaura coupling reaction, nickel precatalyst 3a was active for the coupling of aryl chlorides as well as aryl fluorides. The analogously synthesized Pd(II) complexes resulted in formation of (diNHC)PdCl(2) species which were not active for the coupling of aryl fluorides. For the Mizoroki-Heck reaction, it was found that aryl iodides could be activated in the absence of nickel or palladium precatalysts when using Na(2)CO(3) or NEt(3) as base while aryl iodides and aryl bromides could be activated in the Suzuki-Miyaura reaction sans precatalyst when K(3)PO(4) was used as base.

Noninnocence in Metal Complexes: A Dithiolene Dawn

Noninnocence in inorganic chemistry traces its roots back half a century to work that was done on metal complexes containing unsaturated dithiolate ligands. In a flurry of activity in the early 1960s by three different research groups, homoleptic bis and tris complexes of these ligands, which came to be known as dithiolenes, were synthesized, and their structural, electrochemical, spectroscopic, and magnetic properties were investigated. The complexes were notable for facile one-electron transfers and intense colors in solution, and conventional oxidation-state descriptions could not account for their electronic structures. The bis complexes were, in general, found to be square-planar, including the first examples of this geometry for paramagnetic complexes and different formal d(n) configurations. Several of the neutral and monoanionic tris complexes were found to have trigonal-prismatic coordination, the first time that this geometry had been observed in molecular metal complexes. Electronic structural calculations employing extended Hückel and other semiempirical computational methods revealed extensive ligand-metal mixing in the frontier orbitals of these systems, including the observation of structures in which filled metal-based orbitals were more stable than ligand-based orbitals of the same type, suggesting that the one-electron changes upon oxidation or reduction were occurring on the ligand rather than on the metal center. A summary of this early work is followed with a brief section on the current interpretations of these systems based on more advanced spectroscopic and computational methods. The take home message is that the early work did indeed provide a solid foundation for what was to follow in investigations of metal complexes containing redox-active ligands.

Reactivity of Paramagnetic FeII–Bis(amidinate) Complexes

AbstractSynthesis and characterisation of ether adducts of bis(amidinate) FeII complexes are described [amidinate = 2,6‐iPr2C6H3–NC(Ph)N–Ph]. The isolation of these five‐coordinate complexes contrasts with the homoleptic bis(amidinate) Fe complexes obtained previously with the sterically more demanding amidinate ligands 2,6‐iPr2C6H3–NC(Ph)N–Ar (Ar = 2,6‐iPr2C6H3, 2,6‐Me2C6H3) The more accessible ether adducts show enhanced reactivity towards Lewis bases and towards the π‐acid carbon monoxide. Reaction with excess amounts of CO results in carbonyl insertion into the Fe–N bonds, thereby giving rise to a diamagnetic bis(CO) adduct supported by two carbamoyl ligands.

Optically Active Homoleptic Bis(phthalocyaninato) Rare Earth Double-Decker Complexes Bearing Peripheral Chiral Menthol Moieties: Effect of π−π Interaction on the Chiral Information Transfer at the Molecular Level

With the view to creating novel sandwich-type phthalocyaninato rare earth complexes toward new applications in material science and catalysis, d- and l-enantiomers of a series of optically active homoleptic bis(phthalocyaninato) rare earth double-deckers with four chiral menthol moieties at the peripheral positions of the phthalocyanine ligand, M(Pc*)(2) [Pc* = 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine; M = Eu, Y, Lu] (1-3), have been designed and prepared by treating (d)- or (l)-4-(2-isopropyl-5-methylcyclohexoxyl)-1,2-dicyanobenzene with the corresponding M(acac)(3).nH(2)O (acac = acetylacetonate) in the presence of the organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in refluxing n-pentanol. For the purpose of comparative study, heteroleptic bis(phthalocyaninato) europium analogues (d)- and (l)-Eu(Pc)(Pc*) (4) as well as the unsubstituted homoleptic bis(phthalocyaninato) europium counterpart Eu(Pc)(2) (5) were also prepared. The novel synthesized bis(phthalocyaninato) rare earth double-deckers have been characterized by a wide range of spectroscopic methods including MS, (1)H NMR, IR, and electronic absorption spectroscopic measurements in addition to elemental analysis. In contrast to the CD silent monomeric metal-free 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine, observation of the CD signal in the N absorption region of 4 reveals the significant effect of intramolecular pi-pi interaction on intensifying the asymmetrical perturbation of the chiral menthol units onto the phthalocyanine chromophore, which results in successful chiral information transfer from menthol moieties to the phthalocyanine chromophore at a molecular level in the heteroleptic double-decker compound 4 despite the lack of CD signal in the Soret and Q absorption regions of the phthalocyanine ligand. This is further supported by the optical activity of homoleptic bis(phthalocyaninato) rare earth double-deckers M(Pc*)(2) (1-3), as revealed by the CD signals even in the Soret and Q absorption regions according to the CD spectroscopic result, indicating the intensified asymmetrical perturbation of the chiral menthol units onto the phthalocyanine chromophores along with the increase in the chiral menthol substituent number from 4 to 1-3. The present result at the molecular level is helpful for understanding the chiral information transfer mechanism at the supermolecular level. In addition, the electrochemical properties of bis(phthalocyaninato) rare earth complexes have also been comparatively investigated by cyclic voltammetry and differential pulse voltammetry.