CoCorrole-Functionalized PCN-222 for Carbon Monoxide Selective Adsorption.

The high risk of CO poisoning justifies the need for indoor air quality control and warning systems based on the detection of low concentrations (ppm-ppb) of CO. Cobalt corrole complexes selectively bind CO vs. O2, CO2, N2, opening new fields of applications. By combining the CO chemisorption properties of cobalt corroles with the known sorption capacity of MOFs, we hope to obtain high performance sensing materials for CO detection. In addition, the exposed metal sites of MOFs lead to CO2 physisorption, allowing the co-detection of CO and CO2. In this work, PCN-222, a stable Zr-based MOF made from Ni(TCPP) with natural vacancies, has been used as a porous matrix for the grafting of electron-poor metallocorroles. The materials were characterized by powder XRD, SEM and optical microscopy, BET analyses and gas adsorption measurements at 298 K. No degradation of the crystalline structure of PCN-222 was observed. At 1 atm, the adsorbed CO(g) volumes measured for the best materials were 12.15 cm3 g-1 and 14.01 cm3 g-1 for CoCorr2@PCN-222 and CoCorr3@PCN-222 respectively, and both materials exhibited high CO chemisorption and selectivity against O2, N2, and CO2 at low pressure due to the highest energy of the chemisorption process vs physisorption.

Inverse Hypercorroles.

Ground-state and time-dependent density functional theory (TDDFT) calculations with the long-range-corrected, Coulomb-attenuating CAMY-B3LYP exchange-correlation functional and large, all-electron STO-TZ2P basis sets have been used to examine the potential "inverse hypercorrole" character of meso-p-nitrophenyl-appended dicyanidocobalt(III) corrole dianions. The effect is most dramatic for 5,15-bis(p-nitrophenyl) derivatives, where it manifests itself in intense NIR absorptions. The 10-aryl groups in these complexes play a modulatory role, as evinced by experimental UV-visible spectroscopic and electrochemical data for a series of 5,15-bis(p-nitrophenyl) dicyanidocobalt(III) corroles. TDDFT (CAMY-B3LYP) calculations ascribe these features clearly to a transition from the corrole's a2u-like HOMO (retaining the D4h irrep used for metalloporphyrins) to a nitrophenyl-based LUMO. The outward nature of this transition contrasts with the usual phenyl-to-macrocycle direction of charge transfer transitions in many hyperporphyrins and hypercorroles; thus, the complexes studied are aptly described as inverse hypercorroles.

Synthesis and characterization of new acid-functionalized porphyrins displaying antimicrobial activity against gram positive bacteria, yeasts and filamentous fungi with or without ultra-high irradiance.

The antimicrobial activity of new acid-functionalized porphyrins, with or without ultra-high irradiance, was investigated. Antibacterial efficacy was evaluated against Staphylococcus aureus (methicillin-resistant or methicillin-sensitive strains) and antifungal efficacy was evaluated against the yeast Candida albicans and the filamentous fungi Aspergillus fumigatus. Overall, the porphyrins tested are more effective against S. aureus. The best results were obtained with zinc diacid porphyrins 4 and 5 after only 3 min of ultra-high irradiation (500 mW/cm2, 405 nm), demonstrating that acid-functionalized porphyrins are promising as novel antimicrobial drugs for surface disinfection.

Evaluation of carboxylic acid-derivatized corroles as novel gram-positive antibacterial agents under non-photodynamic inactivation conditions.

Herein, we report the synthesis and evaluation of carboxylic acid corroles bearing either one, two, three of four carboxylic groups as gram-positive antibacterial agents against two strains of S. aureus, one methicillin-sensible (MSSA) and the other methicillin-resistant (MRSA). Lead compounds 5 and 6 show low minimum inhibitory concentrations (MICs) of 0.78 µg/mL against both MSSA and MRSA. These molecules, previously underexplored as antibacterial agents, can now serve as a new scaffold for antimicrobial development.

Altering the Site of Electron Abstraction in Cobalt Corroles via meso-Trifluoromethyl Substituents.

A mono-DMSO cobalt meso-CF3 corrole, formulated as (CF3)3CorCo(DMSO), where (CF3)3Cor is the trianion of 5,10,15-tris(trifluoromethyl)corrole, was synthesized and characterized as to its spectral and electrochemical properties in nonaqueous media with a focus on its coordination chemistry and electronic structure. Cyclic voltammetric measurements showed more facile reductions and difficult oxidations compared to the cobalt triarylcorrole possessing p-CF3Ph units at the meso-positions, a result consistent with the enhanced inductive effect of the electron-withdrawing trifluoromethyl substituents linked directly at the meso-carbon atoms of the macrocycle. The effects of DMSO, pyridine, and cyanide anions (CN-) on the electrochemistry and spectral properties of the compound were investigated, and it was found that only two molar equivalents are needed to form the bis-CN adduct, which exhibited two 1-electron oxidations at 0.27 and 0.95 V vs saturated calomel electrode (SCE) in CH2Cl2/0.1 M TBAP. The sites of electron transfer in the first oxidation and reduction were investigated by spectroelectrochemistry and confirmed that the first electron addition affords a Cor3-CoII complex under all solution conditions independent of the initial coordination and/or electronic configuration (i.e., innocent Cor3-CoIII or noninnocent Cor•2-CoII). In contrast, data for the first oxidation suggests that the site of electron abstraction (ligand or metal) depended upon coordination of the neutral and in situ generated complexes under the various solution conditions, leading to a Co(IV)-corrole3- product for both the bis-pyridine and bis-cyanide adducts.

Corroles at work: a small macrocycle for great applications.

Corrole chemistry has witnessed an impressive boost in studies in the last 20 years, thanks to the possibility of preparing corrole derivatives by simple synthetic procedures. The investigation of a large number of corroles has highlighted some peculiar characteristics of these macrocycles, having features different from those of the parent porphyrins. With this progress in the elucidation of corrole properties, attention has been focused on the potential for the exploitation of corrole derivatives in different important application fields. In some areas, the potential of corroles has been studied in certain detail, for example, the use of corrole metal complexes as electrocatalysts for energy conversion. In some other areas, the field is still in its infancy, such as in the exploitation of corroles in solar cells. Herein, we report an overview of the different applications of corroles, focusing on the studies reported in the last five years.

[Collaboration in home care: first interprofessional ambulatory proximity network]. / Collaboration dans les soins à domicile : un réseau interprofessionnel ambulatoire de proximité.

While interprofessionality is indispensable to respond to home care current issues, its implementation in the practice is a real challenge. The Genevan domiciliary model (reference by a nurse, targeted areas of interventions, etc.) needs to integrate all the resources of proximity. For this purpose, an interprofessional ambulatory and of proximity care network (RIAP) was created, aiming at strengthening the exchanges physicians/nurses about shared patients. RIAP benefits from an encouraging first assessment. Learnings from this experience are used to refine the modeling of this type of proximity network.

Alors que l'interprofessionnalité est indispensable pour répondre aux enjeux actuels du maintien à domicile, sa mise en œuvre dans la pratique représente un véritable défi. Le modèle domiciliaire genevois actuel (référence infirmière, zones d'interventions ciblées, etc.) nécessite d'intégrer toutes les ressources de proximité. Pour ce faire, un réseau de soins interprofessionnel ambulatoire de proximité (RIAP) a été créé, visant au renforcement de l'interprofessionnalité et résolument ancré dans la proximité des différents acteurs. Le RIAP repose notamment sur la consolidation des échanges médecins/infirmières autour de patients communs. Le premier bilan du RIAP est encourageant. Les apprentissages tirés de cette expérience permettent d'affiner la modélisation de ce type de réseau de proximité.

Hypercorroles Formed via the Tail that Wagged the Dog: Charge Transfer Interactions from Innocent Corroles to Meso-Nitrophenyl Substituents.

A series of cobalt nitrophenylcorroles were spectrally characterized in CH2Cl2, and under certain solution conditions, several compounds were shown to exhibit hypercorrole spectra resulting from charge transfer interactions from the corrole π-system to the redox-active meso-NO2Ph substituents. The resulting spectral pattern has not previously been reported for metallocorroles and in the case of the cobalt derivatives was shown to depend upon the number and position of the meso-nitrophenyl groups on the macrocycle, the position of the NO2 substituent on the meso-phenyl ring(s) (para or meta), and the electronic structure of the corrole, which can exist in its innocent or noninnocent form depending in large part upon the type and number of axial ligands. Cobalt corroles bearing p-nitrophenyl groups at the 5,15- or 5,10,15-positions of the macrocycle exhibited the most marked hypercorrole spectra under solution conditions where the complex was innocent (i.e., Cor3-CoIII), and a systematic analysis of the spectral data suggests the root of this perturbation to be a corrole-to-aryl interaction (i.e., ligand-to-ligand charge transfer or LLCT). The largest interaction between the π-system and the NO2Ph substituents was seen upon coordination of anionic cyanide (CN-) axial ligands to the Co(III) center of the bis-(CN-)-5,15-dinitrophenyl derivative, resulting in a cobalt hypercorrole spectrum where the broad Q-band was red-shifted even further into the NIR region and located at 795 nm in CH2Cl2 and 827 nm in pyridine. Cyclic voltammetry of the bis-CN- adducts showed that the first electrons are added to the LUMOs of the p-NO2Ph substituents rather than the corrole, while the same orbitals for the mono-CN- adducts are nearly degenerate. This redox behavior contrasts with what is seen for the noninnocent nitrophenyl corroles having "normal" unperturbed UV-vis spectra where the first reduction involves the π-system of the macrocycle, followed by reduction of the p-NO2Ph groups at more negative potentials.

Identifying G-Quadruplex-DNA-Disrupting Small Molecules.

The quest for small molecules that strongly bind to G-quadruplex-DNA (G4), so-called G4 ligands, has invigorated the G4 research field from its very inception. Massive efforts have been invested to discover or rationally design G4 ligands, evaluate their G4-interacting properties in vitro through a series of now widely accepted and routinely implemented assays, and use them as innovative chemical biology tools to interrogate cellular networks that might involve G4s. In sharp contrast, only uncoordinated efforts aimed at developing small molecules that destabilize G4s have been invested to date, even though it is now recognized that such molecular tools would have tremendous application in neurobiology as many genetic and age-related diseases are caused by an overrepresentation of G4s. Herein, we report on our efforts to develop in vitro assays to reliably identify molecules able to destabilize G4s. This workflow comprises the newly designed G4-unfold assay, adapted from the G4-helicase assay implemented with Pif1, as well as a series of biophysical and biochemical techniques classically used to study G4/ligand interactions (CD, UV-vis, PAGE, and FRET-melting), and a qPCR stop assay, adapted from a Taq-based protocol recently used to identify G4s in the genomic DNA of Schizosaccharomyces pombe. This unique, multipronged approach leads to the characterization of a phenylpyrrolocytosine (PhpC)-based G-clamp analog as a prototype of G4-disrupting small molecule whose properties are validated through many different and complementary in vitro evaluations.

[COGERIA: coordination of care for the frail elderly]. / COGERIA : Coordination des soins de la personne âgée fragile.

COGERIA, a cantonal program is the fruit of a close collaboration between the Geneva General Directorate of Health and the major health and social partners in the canton. The program aims to improve inter-professional care for the frail elderly and to adapt their care pathways in close collaboration with their primary care physicians and home healthcare providers. Launched in May 2019, the program includes more than 283 beneficiaries and 152 primary care physicians in collaboration with the home healthcare providers in the Servette and Meyrin areas. Preliminary results show a possible trend towards a decrease in hospitalizations, as well as major satisfaction from beneficiaries and the COGERIA partners.

La Coordination des soins de la personne âgée fragile est un dispositif cantonal né d'une étroite collaboration entre la Direction générale de la santé et les grands partenaires de la santé et du social à Genève. Ce dispositif œuvre à améliorer la prise en charge interprofessionnelle autour des personnes âgées fragiles et à adapter leurs parcours de soins, en étroite collaboration avec les médecins traitants et les prestataires de soins à domicile. Lancé en mai 2019, le dispositif compte plus de 283 personnes incluses, avec 152 médecins traitants du réseau primaire en collaboration avec l'Institution genevoise de maintien à domicile, ainsi qu'une ouverture récente à tous les prestataires de soins dans les zones de la Servette et de Meyrin. Des résultats préliminaires mettent en évidence une possible tendance à une baisse d'hospitalisations ainsi qu'une grande satisfaction de la part des bénéficiaires et des partenaires.

Solvent and Anion Effects on the Electrochemistry of Manganese Dipyrrin-Bisphenols.

A series of "N2O2-type" manganese dipyrrin-bisphenols (DPP), formulated as (Ar)DPPMn, where Ar = pentafluorophenyl (F5Ph), phenyl (Ph), or mesityl (Mes), were electrochemically and spectroscopically characterized in nonaqueous media with and without added anions in the form of tetrabutylammonium salts (TBAX where X = ClO4-, PF6-, BF4-, F-, Cl-, OH-, or CN-). Two major one-electron reductions are observed under most solution conditions, the first of which is assigned as a MnIII/II process and the second as electron addition to the π-ring system as confirmed by spectroelectrochemistry. Each MnIII complex also exhibits one or two one-electron oxidations, the exact number depending upon the positive potential limit of the electrochemical solvent. The two oxidations are separated by 580-590 mV in CH3CN containing 0.1 M TBAPF6 and are assigned as π-ring-centered electron transfers to stepwise form a (Ar)DPPMnIII π-cation radical and dication under these solution conditions. Comparisons are made between redox properties of (Ar)DPPMn and manganese(III) porphyrins, corroles, and corrolazines each of which contains an innocent trianionic complexing ligand. The redox behavior and spectroscopic properties of [(Ar)DPPMn]n where n = 0, -1, or +1 are also compared to that of other structurally related [(Ar)DPPM]n complexes under similar solution conditions where M = CoII, CuII, BIII, or AuIII.

Synthesis and the Effect of Anions on the Spectroscopy and Electrochemistry of Mono(dimethyl sulfoxide)-Ligated Cobalt Corroles.

A new series of cobalt A3-triarylcorroles were synthesized and the compounds examined as to their electrochemical and spectroscopic properties in CH2Cl2 or dimethyl sulfoxide (DMSO) containing 10 different anions added to the solution in the form of tetrabutylammonium salts. The investigated anions were PF6-, BF4-, HSO4-, ClO4-, Br-, I-, Cl-, OAc-, F-, OTs-, and CN-, all but three of which were found to facilitate reduction of the cobalt corrole in dilute CH2Cl2 solutions, as determined by a combination of UV-vis spectroscopy and spectroelectrochemistry. The synthesized corroles are represented as (Ar)3CorCo(DMSO), where Ar is a meso-phenyl group containing one of 10 different electron-donating or -withdrawing substituents. The axial DMSO ligand was found to dissociate in dilute (10-5 M) CH2Cl2 solutions, but this was not the case at the higher electrochemical concentration of 10-3 M, where the investigated corroles exhibit a rich redox reactivity, undergoing up to five reversible one-electron-transfer reactions under the different solution conditions. The reversible half-wave potentials for generation of the singly oxidized corroles varied by over 1.0 V with a change in the electron-donating or -withdrawing meso-phenyl substituents and type of anion added to the solution, ranging from E1/2 = 0.83 V in one extreme to -0.42 V in the other. Much smaller shifts in the potentials (on the order of ∼210 mV) were observed for the reversible first reduction as a function of changes of the anion and/or corrole substituents, with the only exception being in the case of CN-, where the E1/2 values in CH2Cl2 ranged from +0.08 V in solutions containing 0.1 M TBAClO4 to >-1.8 V upon the addition of CN-.

Old Dog, New Tricks: Innocent, Five-coordinate Cyanocobalt Corroles.

Three mono-CN ligated anionic cobalt A3-triarylcorroles were synthesized and investigated as to their spectroscopic and electrochemical properties in CH2Cl2, pyridine (Py), and dimethyl sulfoxide (DMSO). The newly synthesized corroles provide the first examples of air-stable cobalt corroles with an anionic axial ligand and are represented as [(Ar)3CorCoIII(CN)]-TBA+, where Cor is the trivalent corrole macrocycle, Ar is p-(CN)Ph, p-(CF3)Ph, or p-(OMe)Ph, and TBA+ is the tetra-n-butylammonium (TBA) cation. Multiple redox reactions are observed for each mono-CN derivative with a key feature being a more facile first oxidation and a more difficult first reduction in all three solvents as compared to all previously examined corroles with similar meso- and ß-pyrrole substituents. Formation constants (log K) for conversion of the five-coordinate mono-CN complex to its six-coordinate bis-CN form ranged from 102.8 for Ar = p-(OMe)Ph to 104.7 for Ar = p-(CN)Ph in DMSO as determined by spectroscopic methodologies. The in situ generated bis-CN complexes, represented as [(Ar)3CorCoIII(CN)2]2-(TBA+)2, and the mixed ligand complexes, represented as [(Ar)3CorCoIII(CN)(Py)]-TBA+, were also investigated as to their electrochemical and spectroscopic properties. UV-visible spectra and electrode reactions of the synthesized mono-CN derivatives are compared with the neutral mono-DMSO cobalt corrole complexes and the in situ generated bis-CN and bis-Py complexes, and the noninnocent (or innocent) nature of each cobalt corrole system is addressed. The data demonstrate the ability of the CN- axial ligand(s) to stabilize the high-valent forms of the metallocorrole, leading to systems with innocent macrocyclic ligands. Although a number of six-coordinate cobalt(III) corroles with N-donor ligands were characterized in the solid state, a dissociation of one axial ligand readily occurs in nonaqueous solvents, and this behavior contrasts with the high stability of the currently studied bis-CN adducts in CH2Cl2, pyridine, or DMSO. Linear free energy relationships were elucidated between the meso-phenyl Hammett substituent constants (Σσ) and the measured binding constants, the redox potentials, and the energy of the band positions in the mono-CN and bis-CN complexes in their neutral or singly oxidized forms, revealing highly predictable trends in the physicochemical properties of the anionic corroles.

[Assessing frailty in care practices†: quick reminders in the light of the Covid-19 pandemic]. / Évaluer la fragilité dans les pratiques de soins†: brefs rappels à la lumière de la pandémie de Covid-19.

The Covid-19 pandemic has brought the concept of frailty back to the centre of debate, particularly for its relevance as a determinant of health outcomes. Frailty is concept that has long been a used gerontology. Today, several theoretical models of frailty are proposed in the literature, with as many tools to operationalize it. This article provides a brief outline of the three main models of frailty and the corresponding measurement instruments. The choice of the model as well as the choice of the assessment tool are discussed in the light of the clinical objectives pursued by health professionals. More generally, this article highlights the value of assessing frailty in routine practice to determine health outcomes and adapt care to individual needs.

La pandémie de Covid-19 a ramené le concept de fragilité au centre des débats, notamment pour son intérêt dans l'évaluation du pronostic en santé dans un contexte de menace sanitaire. La fragilité est un concept reconnu en gérontologie de longue date. Aujourd'hui, plusieurs modèles théoriques de la fragilité sont proposés dans la littérature, avec autant d'instruments permettant de l'opérationnaliser. Cet article propose un bref rappel des trois principaux modèles de fragilité ainsi que des instruments de mesure correspondants et de les discuter en fonction des objectifs cliniques poursuivis par les professionnels de la santé. Plus généralement, cet article souligne l'intérêt d'évaluer la fragilité dans une pratique de routine pour déterminer le pronostic de santé et adapter les soins aux besoins des individus.

Ligand Noninnocence in Cobalt Dipyrrin-Bisphenols: Spectroscopic, Electrochemical, and Theoretical Insights Indicating an Emerging Analogy with Corroles.

Three cobalt dipyrrin-bisphenol (DPPCo) complexes with different meso-aryl groups (pentafluorophenyl, phenyl, and mesityl) were synthesized and characterized based on their electrochemistry and spectroscopic properties in nonaqueous media. Each DPPCo undergoes multiple oxidations and reductions with the potentials, reversibility, and number of processes depending on the specific solution conditions, the specific macrocyclic substituents, and the type and number of axially coordinated ligands on the central cobalt ion. Theoretical calculations of the compounds with different coordination numbers are given in the current study in order to elucidate the cobalt-ion oxidation state and the innocence or noninnocence of the macrocyclic ligand as a function of the changes in the solvent properties and degree of axial coordination. Electron paramagnetic resonance spectra of the compounds are obtained to experimentally assess the electron spin state. An X-ray structure of the six-coordinate complex is also presented. The investigated chemical properties of DPPCo compounds under different solution conditions are compared to those of cobalt corroles, where the macrocycle and metal ion also possess formal 3- and 3+ oxidation states in their air-stable forms.

Written interprofessional communication in the context of home healthcare: A qualitative exploration of Swiss perceptions and practices.

The aim of this study was to explore the practices and perceptions of Swiss home care professionals with regards to written interprofessional communication. We analyzed 11 home care notebooks and conducted six focus groups with home health-care professionals in 2015-2016. Interprofessional written communication was rarely explicit. Health professionals reported a lack of clarity about what to document and for whom. They felt unsure how to reconcile the need for confidential information-sharing among health professionals and the desire for patient/families' active involvement. An ideal (electronic) tool should allow patients to formulate goals and use the platform while allowing health professionals to communicate confidentially among themselves in order to avoid information retention.

Electrochemistry of Bis(pyridine)cobalt (Nitrophenyl)corroles in Nonaqueous Media.

A series of bis(pyridine)cobalt corroles with one or three nitrophenyl groups on the meso positions of the corrole macrocycle were synthesized and characterized as to their electrochemical and spectroscopic properties in dichloromethane, benzonitrile, and pyridine. The potentials for each electrode reaction were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV-visible spectra of the neutral, electroreduced, and electroxidized forms of the corroles. The proposed electronic configurations of the initial compounds and the prevailing redox reactions involving the electroactive central cobalt ion, the electroactive conjugated macrocycle, and the electroactive meso-nitrophenyl groups are all discussed in terms of solvent binding and the number of the nitrophenyl groups and other substituents on the meso-nitrophenyl rings of the compounds.

Excited State N-H Tautomer Selectivity in the Singlet Energy Transfer of a Zinc(II)-Porphyrin-Truxene-Corrole Assembly.

An original corrole-containing polyad for S1 energy transfer, in which one zinc(II)-porphyrin donor is linked to two free-base corrole acceptors by a truxene linker, is reported. This polyad exhibits a rapid zinc(II)-porphyrin*→free-base corrole transfer (4.83×1010  s-1 ; 298 K), even faster than the tautomerization in the excited state processes taking advantage of the good electronic communication provided by the truxene bridge. Importantly, the energy transfer process shows approximately 3-fold selectivity for one corrole N-H tautomer over the other even at low temperature (77 K). This selectivity is due to the difference in the J-integral being effective in both the Förster and Dexter mechanisms. The data are rationalized by DFT computations.

Synthesis, Characterization, and Electrochemistry of Open-Chain Pentapyrroles and Sapphyrins with Highly Electron-Withdrawing meso-Tetraaryl Substituents.

A series of open-chain pentapyrroles and sapphyrins with highly electron-withdrawing substituents (i.e., CN, CF3 , or CO2 Me) on the meso-phenyl rings was synthesized and characterized as to the spectral properties, protonation reactions, and electrochemistry in non-aqueous media. The investigated compounds are represented as (Ar)4 PPyH3 and (Ar)4 SapH3 where PPy and Sap correspond to the tri-anion of the open-chain pentapyrrole and sapphyrin, respectively, and Ar=p-CNPh, p-CF3 Ph, or p-CO2 MePh. UV/Vis and 1 H NMR spectroscopy as well as mass spectrometry data are given for the confirmation of the structures for the newly synthesized compounds. An X-ray structure for one of the pentapyrroles, that is, (p-CF3 Ph)4 PPyH3 (2), is also presented. The protonation processes were examined by UV/Vis absorption spectroscopy during the titration of the compounds with trifluoroacetic acid (TFA) in CH2 Cl2 . Equilibrium constants for the protonation reactions were calculated by using both the Hill equation and the mole ratio method. The protonation-initiated conversion of pentapyrroles to sapphyrins upon oxidation was also investigated. Cyclic voltammetry was used to measure the redox potentials in CH2 Cl2 , PhCN, and/or pyridine (Py). Electrochemical properties, protonation constants, and chemical reactions of the six compounds in the two series were then analyzed as a function of the solvent properties and the type of the electron-withdrawing groups on the meso-phenyl rings.

Tetracationic and Tetraanionic Manganese Porphyrins: Electrochemical and Spectroelectrochemical Characterization.

The electrochemistry and spectroelectrochemistry of four tetrapositively charged and two tetranegatively charged porphyrins were characterized in two nonaqueous solvents (dimethyl sulfoxide and N,N-dimethylformamide) containing 0.1 M tetra-n-butylammonium perchlorate. The tetrapositively charged compounds are represented by the tetrapyridylporphyrins [TRPyPM]4+(X-)4, where R is a methyl or [2-[2-(2-methoxy)ethoxy]ethoxy]ethyl group, M = MnIIII, MnIIICl, CuII, or PdII, and X = I- or Cl-. The tetranegatively charged porphyrins are represented by the tetrasulfonato derivatives [TPPSMn(OAc)]4-(NH4+)4 and [TArPSMn(OAc)]4-(NH4+)4, where Ar = 4-O-[2-[2-(2-methoxy)ethoxy]ethoxy]ethylphenyl. Up to seven electrons can be added to the tetrapyridyl porphyrins in three to five reversible reductions, while up to four electrons can be added to the tetrasulfonato derivatives in four reversible processes. Three types of electrochemical behaviors are observed for reduction of the pyridinium groups on the tetrapyridyl porphyrins. One is for the manganese(II) complexes where the four equivalent pyridinium groups are reduced in a single overlapping four-electron-transfer step. Another is for the free-base porphyrin, where four well-separated one-electron reductions occur, while the third is for copper(II) and palladium(II) derivatives, where reduction of the four pyridinium groups proceeds in two well-separated two-electron-transfer steps. The electrochemical and spectroelectrochemical properties were also characterized for a 1:1 mixture of the tetrapositively and tetranegatively charged manganese porphyrins to investigate possible interactions between these two species. An interaction between the two porphyrins was indeed observed in both solvents after electroreduction of the four pyridinium groups, which led to a substantial change in the mechanism for reduction of the pyridinium groups from an initial single overlapping four-electron-reduction process to two well-separated two-electron-transfer processes.