Coronenetetraimide‐Centered Cruciform Pentamers Containing Multiporphyrin Units: Synthesis and Sequential Photoinduced Energy‐ and Electron‐Transfer Dynamics

A series of coronenetetraimide (CorTIm)‐centered cruciform pentamers containing multiporphyrin units, in which four porphyrin units are covalently linked to a CorTIm core through benzyl linkages, were designed and synthesized to investigate their structural, spectroscopic, and electrochemical properties as well as photoinduced electron‐ and energy‐transfer dynamics. These systems afforded the first synthetic case of coroneneimide derivatives covalently linked with dye molecules. The steady‐state absorption and electrochemical results indicate that a CorTIm and four porphyrin units were successfully characterized by the corresponding reference monomers. In contrast, the steady‐state fluorescence measurements demonstrated that strong fluorescence quenching relative to the corresponding monomer units was observed in these pentamers. Nanosecond laser flash photolysis measurements revealed the occurrence of intermolecular electron transfer from triplet excited state of zinc porphyrins to CorTIm. Femtosecond laser‐induced transient absorption measurements for excitation of the CorTIm unit clearly demonstrate the sequential photoinduced energy and electron transfer between CorTIm and porphyrins, that is, occurrence of the initial energy transfer from CorTIm (energy donor) to porphyrins (energy acceptor) and subsequent electron transfer from porphyrins (electron donor) to CorTIm (electron acceptor) in these pentamers, whereas only the electron‐transfer process from porphyrins to CorTIm was observed when we mainly excite porphyrin units. Finally, construction of high‐order supramolecular patterning of these pentamers was performed by utilizing self‐assembly and physical dewetting during the evaporation of solvent.     

Long‐Lived Charge Separation in Novel Axial Donor–Porphyrin–Acceptor Triads Based on Tetrathiafulvalene,Aluminum(III) Porphyrin and Naphthalenediimide

Two self‐assembled supramolecular donor–acceptor triads consisting of Al^III porphyrin (AlPor) with axially bound naphthalenediimide (NDI) as an acceptor and tetrathiafulvalene (TTF) as a secondary donor are reported. In the triads, the NDI and TTF units are attached to Al^III on opposite faces of the porphyrin, through covalent and coordination bonds, respectively. Fluorescence studies show that the lowest excited singlet state of the porphyrin is quenched through electron transfer to NDI and hole transfer to TTF. In dichloromethane hole transfer to TTF dominates, whereas in benzonitrile (BN) electron transfer to NDI is the main quenching pathway. In the nematic phase of the liquid crystalline solvent 4‐(n‐pentyl)‐4′‐cyanobiphenyl (5CB), a spin‐polarized transient EPR spectrum that is readily assigned to the weakly coupled radical pair TTF^.+NDI^.? is obtained. The initial polarization pattern indicates that the charge separation occurs through the singlet channel and that singlet–triplet mixing occurs in the primary radical pair. At later time the polarization pattern inverts as a result of depopulation of the states with singlet character by recombination to the ground state. The singlet lifetime of TTF^.+NDI^.? is estimated to be 200–300 ns, whereas the triplet lifetime in the approximately 350 mT magnetic field of the X‐band EPR spectrometer is about 10 μs. In contrast, in dichloromethane and BN the lifetime of the charge separation is <10 ns.     

Solvent‐Free Photooxidation of Alkanes by Dioxygen with 2,3‐Dichloro‐5,6‐dicyano‐p‐benzoquinone via Photoinduced Electron Transfer

Photooxidation of alkanes by dioxygen occurred under visible light irradiation of 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone (DDQ) which acts as a super photooxidant. Solvent‐free hydroxylation of cyclohexane and alkanes is initiated by electron transfer from alkanes to the singlet and triplet excited states of DDQ to afford the corresponding radical cations and DDQ^??, as revealed by femtosecond laser‐induced transient absorption measurements. Alkane radical cations readily deprotonate to produce alkyl radicals, which react with dioxygen to afford alkylperoxyl radicals. Alkylperoxyl radicals abstract hydrogen atoms from alkanes to yield alkyl hydroperoxides, accompanied by regeneration of alkyl radicals to constitute the radical chain reactions, so called autoxidation. The radical chain is terminated in the bimolecular reactions of alkylperoxyl radicals to yield the corresponding alcohols and ketones. DDQ^??, produced by the photoinduced electron transfer from alkanes to the excited state of DDQ, disproportionates with protons to yield DDQH₂.     

Photoinduced Energy and Electron Transfer in Phenylethynyl‐Bridged Zinc Porphyrin–Oligothienylenevinylene–C60 Ensembles

Donor–bridge–acceptor triad (Por‐2TV‐C₆₀) and tetrad molecules ((Por)₂‐2TV‐C₆₀), which incorporated C₆₀ and one or two porphyrin molecules that were covalently linked through a phenylethynyl‐oligothienylenevinylene bridge, were synthesized. Their photodynamics were investigated by fluorescence measurements, and by femto‐ and nanosecond laser flash photolysis. First, photoinduced energy transfer from the porphyrin to the C₆₀ moiety occurred rather than electron transfer, followed by electron transfer from the oligothienylenevinylene to the singlet excited state of the C₆₀ moiety to produce the radical cation of oligothienylenevinylene and the radical anion of C₆₀. Then, back‐electron transfer occurred to afford the triplet excited state of the oligothienylenevinylene moiety rather than the ground state. Thus, the porphyrin units in (Por)‐2TV‐C₆₀ and (Por)₂‐2TV‐C₆₀ acted as efficient photosensitizers for the charge separation between oligothienylenevinylene and C₆₀.     

Stabilization of the Charge‐Separated States of Covalently Linked Zinc Porphyrin–Triphenylamine–[60]Fullerene

Spectroscopic, redox, computational, and electron transfer reactions of the covalently linked zinc porphyrin–triphenylamine–fulleropyrrolidine system are investigated in solvents of varying polarity. An appreciable interaction between triphenylamine and the porphyrin π system is revealed by steady‐state absorption and emission, redox, and computational studies. Free‐energy calculations suggest that the light‐induced processes via the singlet‐excited porphyrin are exothermic in benzonitrile, dichlorobenzene, toluene, and benzene. The occurrence of fast and efficient charge‐separation processes (≈10¹² s^?1) via the singlet‐excited porphyrin is confirmed by femtosecond transient absorption measurements in solvents with dielectric constants ranging from 25.2 (benzonitrile) to 2.2 (benzene). The rates of the charge separation processes are much less solvent‐dependent, which suggests that the charge‐separation processes occur at the top region of the Marcus parabola. The lifetimes of the singlet radical‐ion pair (70–3000 ps at room temperature) decrease substantially in more polar solvents, which suggests that the charge‐recombination process is occurring in the Marcus inverted region. Interestingly, by utilizing the nanosecond transient absorption spectral technique we can obtain clear evidence about the existence of triplet radical‐ion pairs with relatively long lifetimes of 0.71 μs (in benzonitrile) and 2.2 μs (in o‐dichlorobenzene), but not in toluene and benzene due to energetic considerations. From the point of view of mechanistic information, the synthesized zinc porphyrin–triphenylamine–fulleropyrrolidine system has the advantage that both the lifetimes of the singlet and triplet radical‐ion pair can be determined.     

Photoinduced Electron Transfer between N,N, Nr,N' ‐Tetra‐(p‐methylphenyl)‐4, 4‐diamino‐1, 1'‐diphenyl Ether (TPDAE) and Fullerenes (C60/C70) by Laser Flash Photolysis

The photoinduced electron‐transfer reaction of N, N, N', N'‐tetra‐(p‐methylphenyl)‐4,4'‐diamino‐1,1'‐diphenyl ether (TPDAE) and fullerenes (C₆₀/C₇₀) by nanosecond laser flash photolysis occurred in benzonitrile. Transient absorption spectral measurements were carried out during 532 nm laser flash photolysis of a mixture of the fullerenes (C₆₀/C₇₀) and TPDAE. The electron transfer from the TPDAE to excited triplet state of the fullerenes (C₆₀/C₇₀) quantum yields and rate constants of electron transfer from TPDAE to excited triplet state of fullerenes (C₆₀/C₇₀) in benzonitrile have been evaluated by observing the transient absorption bands in the near‐IR region where the excited triplet state, radical anion of fullerenes (C₆₀/C₇₀) and radical cations of TPDAE are expected to appear.     

Photochemical Evidence of Electronic Interwall Communication in Double‐Wall Carbon Nanotubes

Single‐ and double‐wall carbon nanotubes (CNTs) having dimethylanilino (DMA) units covalently attached to the external graphene wall have been prepared by the reaction of the dimethylaminophenylnitronium ion with the corresponding CNT. The samples have been characterized by Raman and XPS spectroscopies, thermogravimetry, and high‐resolution transmission electron microscopy in which the integrity of the single or double wall of the CNT and the percentage of substitution (one dimethylanilino group every 45 carbons of the wall for the single‐ and double‐wall samples) has been determined. Nanosecond laser flash photolysis has shown the generation of transients that has been derived from the charge transfer between the dimethylanilino (as the electron donor) to the CNT graphene wall (as the electron acceptor). Importantly, the lifetime of the double‐wall CNT is much shorter than that monitored for the single‐wall CNT. Shorter‐lived transients were also observed for the pentyl‐esterified functionalized double‐wall CNT with respect to the single‐wall analogue in the presence of hole (CH₃OH) and electron quenchers (O₂, N₂O), which has led to the conclusion that the inner, intact graphene wall that is present in double‐wall CNT increases the charge mobility significantly, favoring charge recombination processes. Considering the importance that charge mobility has in microelectronics, our finding suggests that double‐wall CNT or two‐layer graphene may be more appropriate to develop devices needing fast charge mobility.     

Tuning Excited‐State Reactivity by Proton‐Coupled Electron Transfer

The reactivity, and even reaction pathway, of excited states can be tuned by proton‐coupled electron transfer (PCET). The triplet state of benzophenone functionalized with a Brønsted acid (³*BP‐COOH) showed a more powerful oxidation capability over the simple triplet state of benzophenone (³*BP). ³*BP‐COOH could remove an electron from benzene at the rate of 8.0×10⁵ m ^?1 s^?1, in contrast to the reactivity of ³*BP which was inactive towards benzene oxidation. The origin of this great enhancement on the ability of the excited states to remove electrons from substrates is attributed to the intramolecular Brønsted acid, which enables the reductive quenching of ³*BP by concerted electron–proton transfer.     

Unraveling the Mechanism of the Photodeprotection Reaction of 8‐Bromo‐ and 8‐Chloro‐7‐hydroxyquinoline Caged Acetates

Photoremovable protecting groups (PPGs) when conjugated to biological effectors forming “caged compounds” are a powerful means to regulate the action of physiologically active messengers in vivo through 1‐photon excitation (1PE) and 2‐photon excitation (2PE). Understanding the photodeprotection mechanism is important for their physiological use. We compared the quantum efficiencies and product outcomes in different solvent and pH conditions for the photolysis reactions of (8‐chloro‐7‐hydroxyquinolin‐2‐yl)methyl acetate (CHQ‐OAc) and (8‐bromo‐7‐hydroxyquinolin‐2‐yl)methyl acetate (BHQ‐OAc), representatives of the quinoline class of phototriggers for biological use, and conducted nanosecond time‐resolved spectroscopic studies using transient emission (ns‐EM), transient absorption (ns‐TA), transient resonance Raman (ns‐TR²), and time‐resolved resonance Raman (ns‐TR³) spectroscopies. The results indicate differences in the photochemical mechanisms and product outcomes, and reveal that the triplet excited state is most likely on the pathway to the product and that dehalogenation competes with release of acetate from BHQ‐OAc, but not CHQ‐OAc. A high fluorescence quantum yield and a more efficient excited‐state proton transfer (ESPT) in CHQ‐OAc compared to BHQ‐OAc explain the lower quantum efficiency of CHQ‐OAc relative to BHQ‐OAc.     

Electron Transfer between Hydrogen‐Bonded Pyridylphenols and a Photoexcited Rhenium(I) Complex

Two pyridylphenols with intramolecular hydrogen bonds between the phenol and pyridine units have been synthesized, characterized crystallographically, and investigated by cyclic voltammetry and UV/Vis spectroscopy. Reductive quenching of the triplet metal‐to‐ligand charge‐transfer excited state of the [Re(CO)₃(phen)(py)]⁺ complex (phen=1,10‐phenanthroline, py=pyridine) by the two pyridylphenols and two reference phenol molecules is investigated by steady‐state and time‐resolved luminescence spectroscopy, as well as by transient absorption spectroscopy. Stern–Volmer analysis of the luminescence quenching data provides rate constants for the bimolecular excited‐state quenching reactions. H/D kinetic isotope effects for the pyridylphenols are on the order of 2.0, and the bimolecular quenching reactions are up to 100 times faster with the pyridylphenols than with the reference phenols. This observation is attributed to the markedly less positive oxidation potentials of the pyridylphenols with respect to the reference phenols (≈0.5 V), which in turn is caused by proton coupling of the phenol oxidation process. Transient absorption spectroscopy provides unambiguous evidence for the photogeneration of phenoxyl radicals, that is, the overall photoreaction is clearly a proton‐coupled electron‐transfer process.     

Photoinduced Triplet–Triplet Energy Transfer in a 2‐Ureido‐4(1H)‐Pyrimidinone‐Bridged,Quadruply Hydrogen‐Bonded Ferrocene–Fullerene Assembly

2‐Ureido‐4(1H)‐pyrimidinone‐bridged ferrocene–fullerene assembly I is designed and synthesized for elaborating the photoinduced electron‐transfer processes in self‐complementary quadruply hydrogen‐bonded modules. Unexpectedly, steady‐state and time‐resolved spectroscopy reveal an inefficient electron‐transfer process from the ferrocene to the singlet or triplet excited state of the fullerene, although the electron‐transfer reactions are thermodynamically feasible. Instead, an effective intra‐assembly triplet–triplet energy‐transfer process is found to be operative in assembly I with a rate constant of 9.2×10⁵ s^?1 and an efficiency of 73 % in CH₂Cl₂ at room temperature.     

Strong Visible‐Light‐Absorbing Cuprous Sensitizers for Dramatically Boosting Photocatalysis

Developing strong visible‐light‐absorbing (SVLA) earth‐abundant photosensitizers (PSs) for significantly improving the utilization of solar energy is highly desirable, yet it remains a great challenge. Herein, we adopt a through‐bond energy transfer (TBET) strategy by bridging boron dipyrromethene (Bodipy) and a Cu^I complex with an electronically conjugated bridge, resulting in the first SVLA Cu^I PSs ( Cu‐2 and Cu‐3 ). Cu‐3 has an extremely high molar extinction coefficient of 162 260 m ^?1 cm^?1 at 518 nm, over 62 times higher than that of traditional Cu^I PS ( Cu‐1 ). The photooxidation activity of Cu‐3 is much greater than that of Cu‐1 and noble‐metal PSs (Ru(bpy)₃²⁺ and Ir(ppy)₃⁺) for both energy‐ and electron‐transfer reactions. Femto‐ and nanosecond transient absorption and theoretical investigations demonstrate that a “ping‐pong” energy‐transfer process in Cu‐3 involving a forward singlet TBET from Bodipy to the Cu^I complex and a backward triplet‐triplet energy transfer greatly contribute to the long‐lived and Bodipy‐localized triplet excited state.     

Photoinduced Electron Transfer in Tetrathiafulvalene−Porphyrin−Fullerene Molecular Triads

The two molecular triads 1a and 1b consisting of a porphyrin (P) covalently linked to a fullerene (C₆₀) electron acceptor and tetrathiafulvalene (TTF) electron‐donor moiety were synthesized, and their photochemical properties were determined by transient absorption and emission techniques. Excitation of the free‐base‐porphyrin moiety of the TTF−P_{2 H}−C₆₀ triad 1a in tetrahydro‐2‐methylfuran solution yields the porphyrin first excited singlet state TTF−¹P_{2 H}−C₆₀, which undergoes photoinduced electron transfer with a time constant of 25 ps to give TTF−P_{2 H}^.+−C₆₀^.−. This intermediate charge‐separated state has a lifetime of 230 ps, decaying mainly by a charge‐shift reaction to yield a final state, TTF^.+−P_{2 H}−C₆₀^.−. The final state has a lifetime of 660 ns, is formed with an overall yield of 92%, and preserves ca. 1.0 eV of the 1.9 eV inherent in the porphyrin excited state. Similar behavior is observed for the zinc analog 1b . The TTF‐P_Zn^.+−C₆₀^.− state is formed by ultrafast electron transfer from the porphyrinatozinc excited singlet state with a time constant of 1.5 ps. The final TTF^.+−P_Zn−C₆₀^.− state is generated with a yield of 16%, and also has a lifetime of 660 ns. Although charge recombination to yield a triplet has been observed in related donor‐acceptor systems, the TTF^.+−P−C₆₀^.− states recombine to the ground state, because the molecule lacks low‐energy triplet states. This structural feature leads to a longer lifetime for the final charge‐separated state, during which the stored energy could be harvested for solar‐energy conversion or molecular optoelectronic applications.     

Photophysical Properties and Photoinduced Electron Transfer between[60]Fullerene—containing Cyclic Sulphoxide [C60—C60H8SO]and Tetrathiafulvalene（TTF） by Laser Flash Photolysis

Photoinduced electron transfer(PET) processes between C60-C6H8SO and Tetrathiafulvalene(TTF) have been studied by nanosecond laser photolysis.Quantrm yiekds(φet) and rate constants of electron transfer(ket) from TTF to excited triplet state of[60] fullerene-containing cyclic sulphoxide in benzonitrile(BN) have been evaluated by observing the transient absorption bands in the NIR region.With the decay of excited triplet state of [60]fullerene-containing cyclic suplhoxide,the rise of radical anion of [60]fullerene-containing cyclic sulphoxinde is observed.     

Synthesis,Structural Characterization,Photophysics, and Broadband Nonlinear Absorption of a Platinum(II) Complex with the 6‐(7‐Benzothiazol‐2′‐yl‐9,9‐diethyl‐9 H‐fluoren‐2‐yl)‐2,2′‐bipyridinyl Ligand

A platinum complex with the 6‐(7‐benzothiazol‐2′‐yl‐9,9‐diethyl‐9H‐fluoren‐2‐yl)‐2,2′‐bipyridinyl ligand ( 1 ) was synthesized and the crystal structure was determined. UV/Vis absorption, emission, and transient difference absorption of 1 were systematically investigated. DFT calculations were carried out on 1 to characterize the electronic ground state and aid in the understanding of the nature of low‐lying excited electronic states. Complex 1 exhibits intense structured ¹π–π* absorption at λ_abs<440 nm, and a broad, moderate ¹M LCT/¹LLCT transition at 440–520 nm in CH₂Cl₂ solution. A structured ³π–π*/³M LCT emission at about 590 nm was observed at room temperature and at 77 K. Complex 1 exhibits both singlet and triplet excited‐state absorption from 450 nm to 750 nm, which are tentatively attributed to the ¹π–π* and ³π–π* excited states of the 6‐(7‐benzothiazol‐2′‐yl‐9,9‐diethyl‐9H‐fluoren‐2‐yl)‐2,2′‐bipyridine ligand, respectively. Z‐scan experiments were conducted by using ns and ps pulses at 532 nm, and ps pulses at a variety of visible and near‐IR wavelengths. The experimental data were fitted by a five‐level model by using the excited‐state parameters obtained from the photophysical study to deduce the effective singlet and triplet excited‐state absorption cross sections in the visible spectral region and the effective two‐photon absorption cross sections in the near‐IR region. Our results demonstrate that 1 possesses large ratios of excited‐state absorption cross sections relative to that of the ground‐state in the visible spectral region; this results in a remarkable degree of reverse saturable absorption from 1 in CH₂Cl₂ solution illuminated by ns laser pulses at 532 nm. The two‐photon absorption cross sections in the near‐IR region for 1 are among the largest values reported for platinum complexes. Therefore, 1 is an excellent, broadband, nonlinear absorbing material that exhibits strong reverse saturable absorption in the visible spectral region and large two‐photon‐assisted excited‐state absorption in the near‐IR region.     

Inherent Photon Energy Recycling Effects in the Up‐Converted Delayed Luminescence Dynamics of Poly(fluorene)–PtIIoctaethyl Porphyrin Blends

We present results of steady‐state and transient photoluminescence studies of molecularly doped poly(fluorene) films. We study blends with increasing content of the triplet emitter (2,3,7,8,12,13,17,18‐octaethyl‐porphyrinato)Pt^II (PtOEP) when dispersed in the polymeric poly(fluorene) matrix of the poly[9,9‐di‐(2‐ethylhexyl)‐fluorenyl‐2,7‐diyl] (PF26) derivative. We carry out a unified study of the photophysical reactions that are involved in the energy transfer processes in this system by probing the three luminescence processes of a) PF26 fluorescence, b) triplet–triplet annihilation (TTA) induced up‐converted PF26 delayed fluorescence and c) PtOEP phosphorescence. With increasing PtOEP content, the process of photon energy recycling in the PF26:PtOEP system is manifested from the quenching of the TTA‐induced up‐converted PF26 delayed fluorescence and it is rationalized with the use of Forster theory of resonant energy transfer. Based on the combined results of the photophysical and the transmission electron microscopy characterization of the as‐spun PF26:PtOEP films, we determine the onset of PtOEP aggregation at 2–3 wt % PtOEP content. The analysis of the photophysical data is based on the use of modified Stern–Volmer photokinetic models that are appropriate for the solid state. A static component in the PL quenching of PF26 is revealed for PtOEP contents below 2 wt %. The modified Stern–Volmer kinetic scheme further suggests that co‐aggregation effects between PF26 and PtOEP are operative with an association constant of ground state complex formation k_bind ～15–17 M ^?1. The involvement of the ground state heterospecies in the TTA‐mediated PF26 up‐converted luminescence is discussed. The participation of an electron‐exchange step, in the excited state energy transfer pathway between PtOEP and PF26, is proposed for the activation mechanism of the PF26 up‐converted fluorescence.     

Cocrystals Strategy towards Materials for Near‐Infrared Photothermal Conversion and Imaging

A cocrystal strategy with a simple preparation process is developed to prepare novel materials for near‐infrared photothermal (PT) conversion and imaging. DBTTF and TCNB are selected as electron donor (D) and electron acceptor (A) to self‐assemble into new cocrystals through non‐covalent interactions. The strong D–A interaction leads to a narrow band gap with NIR absorption and that both the ground state and lowest‐lying excited state are charge transfer states. Under the NIR laser illumination, the temperature of the cocrystal sharply increases in a short time with high PT conversion efficiency (η=18.8 %), which is due to the active non‐radiative pathways and inhibition of radiative transition process, as revealed by femtosecond transient absorption spectroscopy. This is the first PT conversion cocrystal, which not only provides insights for the development of novel PT materials, but also paves the way of designing functional materials with appealing applications.     

Aromatic Monochlorination Photosensitized by DDQ with Hydrogen Chloride under Visible‐Light Irradiation

Photochlorination of aromatic substrates by hydrogen chloride with 2,3‐dichloro‐5,6‐cyano‐p‐benzoquinone (DDQ) occurs efficiently to produce the corresponding monochlorinated products selectively under visible‐light irradiation. The yields for the chlorination of phenol were 70 % and 18 % for p‐ and o‐chlorophenol, respectively, without formation of further chlorinated products. The photoinduced chlorination is initiated by electron transfer from Cl^? to the triplet excited state of DDQ. The radical intermediates involved in the photochemical reaction have been detected by time‐resolved transient absorption measurements.     

Chitosan‐Functionalized Carbon Nanotubes as Support for the High Dispersion of PtRu Nanoparticles and their Electrocatalytic Oxidation of Methanol

Carbon nanotubes (CNTs) were non‐covalently functionalized with chitosan (Chit) and then employed as the support for PtRu nanoparticles. The functionalization was carried out at room temperature without the use of corrosive acids, thereby preserving the integrity and the electronic conductivity of the CNTs. Transmission electron microscopy reveals that PtRu nanoparticles were highly dispersed on the surface of Chit‐functionalized CNTs (CNT‐Chit) with small particle‐size. Cyclic voltammetry studies indicated that the PtRu nanoparticle/CNT‐Chit nanohybrids have a higher electrochemical surface area, electrocatalytic performance, and stability towards methanol oxidation compared to PtRu nanoparticles supported on the pristine CNTs.     

Ultrafast Photoinduced Energy and Electron Transfer in Multi‐Modular Donor–Acceptor Conjugates

New multi‐modular donor–acceptor conjugates featuring zinc porphyrin (ZnP), catechol‐chelated boron dipyrrin (BDP), triphenylamine (TPA) and fullerene (C₆₀), or naphthalenediimide (NDI) have been newly designed and synthesized as photosynthetic antenna and reaction‐center mimics. The X‐ray structure of triphenylamine‐BDP is also reported. The wide‐band capturing polyad revealed ultrafast energy‐transfer (k_ENT=1.0×10¹² s^?1) from the singlet excited BDP to the covalently linked ZnP owing to close proximity and favorable orientation of the entities. Introducing either fullerene or naphthalenediimide electron acceptors to the TPA‐BDP‐ZnP triad through metal–ligand axial coordination resulted in electron donor–acceptor polyads whose structures were revealed by spectroscopic, electrochemical and computational studies. Excitation of the electron donor, zinc porphyrin resulted in rapid electron‐transfer to coordinated fullerene or naphthalenediimide yielding charge separated ion‐pair species. The measured electron transfer rate constants from femtosecond transient spectral technique in non‐polar toluene were in the range of 5.0×10⁹–3.5×10¹⁰ s^?1. Stabilization of the charge‐separated state in these multi‐modular donor–acceptor polyads is also observed to certain level.