Terminal Phenyl Group Research Articles

Shared Binding Mode of Perrottetinene and Tetrahydrocannabinol Diastereomers inside the CB1 Receptor May Incentivize Novel Medicinal Drug Design: Findings from an in Silico Assay.

In recent years, therapeutic compounds derived from phytocannabinoids have brought renewed attention to the benefits they offer to ameliorate chronic disease symptoms. Among cannabinoids, tetrahydrocannabinol (THC) is a well-known component of the Cannabis plant, whose active principles have been studied through the years. Another psychoactive phytocannabinoid, derived from liverworts Radula, perrottetinene (PET), has created interest, especially as a pharmaceutical product and for its legal recreational use. Unfortunately, so far, the interaction mode of these compounds at the type 1 cannabinoid receptors (CB1R) binding site remains unknown, and no experimental three-dimensional structure in complex with THC or PET is available in the Protein Data Bank. Today, many computational methodologies can assist in this crusade and help unveil how these molecules bind, based on the already known pose of a structurally similar compound. In this work, we aim to elucidate the binding mode of THC and PET molecules in both cis and trans conformers, using a combination of several computational methodologies, including molecular docking, molecular dynamics, free energy calculations, and protein-energy network studies. We found that THC and PET interact similarly with the CB1R, in a different conformation depending on the considered diastereomer. We have observed that cis ligands adopted a half-chair conformation of the cycle ring containing the dimethyl group, assuming an axial or equatorial conformation producing a different induced fitting of the surrounding residues compared with trans ligands, with higher interaction energy than the trans conformer. For PET, we have seen that Trp-279 and Trp-356 have a marked influence on the binding. After binding, Trp-279 accommodates its side chain to better interact with the PET's terminal phenyl group, disturbing CB1R residues communication. The interaction with Trp-356 might impair the activation of CB1R and can influence the binding of PET as a partial agonist. Understanding the PET association with CB1R from a molecular perspective can offer a glimpse of preventing potential toxicological or recreational effects since it is an attractive lead for drug development with fewer side effects than trans-THC.

Antitubercular and Antiparasitic 2-Nitroimidazopyrazinones with Improved Potency and Solubility.

Following the approval of delamanid and pretomanid as new drugs to treat drug-resistant tuberculosis, there is now a renewed interest in bicyclic nitroimidazole scaffolds as a source of therapeutics against infectious diseases. We recently described a nitroimidazopyrazinone bicyclic subclass with promising antitubercular and antiparasitic activity, prompting additional efforts to generate analogs with improved solubility and enhanced potency. The key pendant aryl substituent was modified by (i) introducing polar functionality to the methylene linker, (ii) replacing the terminal phenyl group with less lipophilic heterocycles, or (iii) generating extended biaryl side chains. Improved antitubercular and antitrypanosomal activity was observed with the biaryl side chains, with most analogs achieved 2- to 175-fold higher activity than the monoaryl parent compounds, with encouraging improvements in solubility when pyridyl groups were incorporated. This study has contributed to understanding the existing structure–activity relationship (SAR) of the nitroimidazopyrazinone scaffold against a panel of disease-causing organisms to support future lead optimization.

Luminescent mesogenic dimeric borondifluoride complexes

ABSTRACT Two new families of dimeric borondifluoride complexes derived from β-enaminoketones containing terminal phenyl and naphthalenyl groups were prepared, and their mesomorphic and optical properties investigated. One single crystallographic structure of mesogenic complex 1a-BF2 (n = 12) was determined by X-ray analysis; it crystallises in a monoclinic space group P21/c and the geometry on boron atoms was all tetrahedral. The crystal was considered as linear-shaped with a length of ~51.95 Å. A relatively large dihedral angle of ~38.85° between the central phenyl spacer and tetrahedral BF2 moiety was observed. Mesomorphic properties were crucially impacted by the structure of the central spacer and terminal group; all bis(borondifluoride) complexes formed SmC or SmA phase except complexes 1b-BF2 (m = 2, 3) and 1c-BF2 . H–bond interactions supported by FT-IR spectra were attributed to the induction of SmA phase in compound 2 c-BF2 . The optical property of the boron complexes was related with their molecular structures, and they emitted blue-to-green emissions at λmax = 420–538 nm in CH2Cl2. This is the first twin liquid crystal of bis(BF2) complexes derived from Schiff baseβ-enaminoketones.

Cooperative Aggregations of Nitrogen-Containing Perylene Diimides Driven by Rigid and Flexible Functional Groups

Variation of aggregated structures driven by side chains is a crucial issue in organic semiconductors (OSCs) for achieving high carrier mobility and device durability. In this work, phenylalkyl side chains composed of a rigid terminal phenyl group and a flexible alkyl linker were studied based on a state-of-the-art n-type π-electron system, 3,4,9,10-benzo­[de]­isoquinolino­[1,8-gh]­quinolinetetracarboxylic diimide (BQQDI), from the viewpoints of aggregated structures and thin-film transistors. An appropriate length of the alkyl, i.e., propyl, linker led to stable formation of a unique aggregated structure regardless of solution-grown single-crystal and vacuum-deposited polycrystalline thin films likely due to cooperation of rigid phenyl and flexible alkyl moieties. In contrast, a shorter ethyl linker showed polymorphism in the polycrystalline film. An absence of polymorphism did not only result in high mobility and low threshold voltage but also show low contact resistance. Hence, this work proposes opportunities to design n-type OSCs by introduction of both rigid and flexible characters to the side chains.

Oxaphosphacyclophanes Constructed from a Bis(triphenylphosphine oxide) Moiety Linked by Dioxyalkyl Chains: Synthesis and Crystal Structures.

Oxaphosphacyclophanes, a bis(triphenylphosphine oxide) moiety linked by dioxypropane, dioxybutane, dioxypentane, and dioxyhexane, were synthesized from the reaction of bis(4-hydroxyphenyl)phenylphosphine oxide and dibromoalkanes. Single-crystal X-ray diffraction analysis and exploring intermolecular interactions by using the Hirshfeld surface revealed that the butylene-linked oxaphosphacyclophane (2) had a one-dimensional (1D) supramolecular structure via CH/π interactions between the terminal phenyl group of 2 and a phenylene group of the cavities. In the packing diagram of pentylene-linked oxaphosphacyclophane (3) with antiform, one macrocycle recognized two terminal phenyl groups to form a 1D supramolecular chain via π/π interactions. The syn-form of 3 was obtained by the recrystallization from toluene and CHCl3. In this crystal, a toluene molecule avoid construction of a 1D chain. The antiform of hexylene-linked oxaphosphacyclophane 4 was obtained by the recrystallization from cyclohexane and CHCl3. Cyclohexane was captured in the cavity via CH/π interactions. Two molecules of 4 with the syn-form recognized each other to construct a dimeric structure via CH/π interactions.

Synthesis, crystal structures, optoelectronic properties and resistive memory application of π-conjugated heteroaromatic molecules

Three π-conjugated small molecules DPBT, DEPBT and DEPBPy, based on bithiazole or bipyridine were designed and synthesized. In DEPBT and DEPBPy, the central core and terminal phenyl groups are connected by CC double bonds, whereas in DPBT, they are combined through C–C single bonds. The effects of the molecular structural changes on their crystal structures, optoelectronic properties and thin film morphologies were comparatively studied. In addition, their resistive memory performance was primarily investigated for the first time. Both DEPBT- and DEPBPy-based devices exhibit typical binary memory behavior, while DPBT-based device presents no memory property. The experimental results confirm that the introduction of CC bridged bonds into molecules could enhance the molecular interaction, which plays an important role in the molecular arrangement on the thin film, and has a significant contribution to charge transport in memory devices. This work demonstrates that aryl vinyl terminated bithiazoles and bipyridines both are good promising candidates for organic memory storage.

Click chemistry towards thermally reversible photochromic 4,5-bisthiazolyl-1,2,3-triazoles.

Three new diarylethenes were synthesized from 1,2-bis(5-methyl-2-(4-substituted-phenyl)thiazol-4-yl)ethyne and benzyl azide through Ru(I)-catalyzed Huisgen cyclization reactions. The 4,5-bisthiazolyl-1,2,3-triazoles thus prepared, which belong to the terarylene family, showed thermally reversible photochromism. The absorption maximum wavelengths of the closed forms are longer than other terarylenes reported so far. The thermal back reactions are much faster when the substituents on the terminal phenyl groups are electron-withdrawing cyano groups than when they are electron-donating methoxy groups.

Synthesis, biological evaluation, and structure activity relationship (SAR) study of pyrrolidine amide derivatives as N-acylethanolamine acid amidase (NAAA) inhibitors.

N-Acylethanolamine acid amidase (NAAA) is one of the key enzymes involved in the degradation of fatty acid ethanolamides (FAEs), especially for palmitoylethanolamide (PEA). Pharmacological blockage of NAAA restores PEA levels, providing therapeutic benefits in the management of inflammation and pain. In the current work, we showed the structure-activity relationship (SAR) studies for pyrrolidine amide derivatives as NAAA inhibitors. A series of aromatic replacements or substituents for the terminal phenyl group of pyrrolidine amides were examined. SAR data showed that small lipophilic 3-phenyl substituents were preferable for optimal potency. The conformationally flexible linkers increased the inhibitory potency of pyrrolidine amide derivatives but reduced their selectivity toward fatty acid amide hydrolase (FAAH). The conformationally restricted linkers did not enhance the inhibitor potency toward NAAA but improved the selectivity over FAAH. Several low micromolar potent NAAA inhibitors were developed, including 4g bearing a rigid 4-phenylcinnamoyl group. Dialysis and kinetic analysis suggested that 4g inhibited NAAA via a competitive and reversible mechanism. Furthermore, 4g showed high anti-inflammatory activities in lipopolysaccharide (LPS) induced acute lung injury (ALI) model, and this effect was blocked by pre-treatment with the PPAR-α antagonist MK886. We anticipate that 4g (E93) will enable a new agent to treat inflammation and related diseases.

Epoxy composites with increased operational characteristics, filled with dispersed mineral fillers

The aim of this work is to increase the physicochemical, deformation and strength properties and to reduce the combustibility of composites on the base of epoxy resin by introducing a oligo(resorcinophenyl phosphate) with terminal phenyl groups Fyrolflex - modifier of polyfunctional action, and disperse mineral fillers – diorite and chromite. Result of the studies established that the optimum amount of modifier in the composition of the epoxy resin is 40 mass parts, which provides an increase in the operational properties of the composites: the breaking stress at bending increases by 2 times, the breaking stress at compression increases by 28%, the impact strength increases twice, while the modulus of elasticity and hardness of composites slightly decrease. The addition of modifier into the epoxy polymer provides an increase in heat resistance from 86 to 132–156 °C, also it improves the thermal stability of the composite, which manifests itself in a shift from the initial temperature to higher temperatures (from 200 to 230 °C), while it is noticed furthermore that yield of carbonized Structures was risen from 40 to 54%, providing less release of volatile pyrolysis products into the gas phase, which leads to the decrease in flammability of the epoxy composite and it can be shown in the reduction of its loss in mass while cauterizing in air from 78 to about 4.7% and an increase in the oxygen index from 19 to 28% by volume what transfers the material into class with low flammability. The rational content of diorite and chromite (100 parts by weight of chromite and 50 parts by mass of diorite) is chosen as a filler, which ensures an increase in physical and mechanical characteristics and a reduction in the cost of production: the breaking stress increases by 15–30% and the elastic modulus at bending increases 3.5–4.5 times, the breaking stress increases by 35%, and the tensile modulus by 50–240%, the hardness increases by 68–95%, while the impact strength remains at the level of the unfilled plasticized composite. In addition, it is proved that the addition of both diorite and chromite provides an increase in the thermal and heat resistance of epoxy composites, also lowers combustibility of the epoxy composite: the weight loss at ignition in air is reduced to 1.2–2.2% and the oxygen index rises from 28 to 30–35% by volume, thus the material does not support combustion in air and belongs to the class of hardly flammable. The study was carried out with the financial support of a grant for young scientists of the SSTU named after Gagarin Yu.A. (project SGTU-287).

Effect of Finely Dispersed Chromite on the Physicochemical and Mechanical Properties of Modified Epoxy Composites

Fylolflex oligo(resorsinol phenyl phosphate) with terminal phenyl groups is an effective plasticizer for an epoxy polymer, allowing the development of compounds with enhanced levels of physicomechanical properties, heat resistance, softening point, an flame resistance. Introduction of chromite, a cheap and active filler, into the epoxy polymer in amounts of 0.1 and 100 wt parts enhances the physicochemical and mechanical properties of the composite. Namely, the Vicat softening point increases from 132 to 140–250°С, the degradation onset temperature increases, and the yield of carbonized structures increases from 54 to 68–86 wt %, which leads to a decrease in the release of volatile pyrolysis products into the gas phase and in the combustibility of the epoxy composite.

Novel Catechol Derivatives of Arylimidamides as Antileishmanial Agents.

Two novel bis-arylimidamide derivatives with terminal catechol moieties (9a and 10a) and two parent compounds with terminal phenyl groups (DB613 and DB884) were synthesized as dihydrobromide salts (9b and 10b). The designed compounds were hybrid molecules consisting of a catechol functionality embedded in an arylimidamide moiety. All compounds were examined for invitro antiparasitic activity upon promastigotes of Leishmania major and L.infantum as well as axenic amastigotes of L.major. It was shown that conversion of terminal phenyl groups into catechol moieties resulted in more than 10-fold improvement in potency, coupled with lower cytotoxicity against fibroblast cells, compared to the corresponding parent compounds. The furan-containing analog 9a exhibited the highest activity with submicromolar IC50 values, ranging from 0.29 to 0.36μm, which is comparable in efficacy to the reference drug amphotericin B (IC50 0.28-0.33μm). The results justify further study of this class of compounds. It seems that the combination of catechol chelating groups with potent antiparasitic agents could improve the efficacy by presenting novel hybrid compounds.

Inversion of Odd-Even Effect Observed in the Crystal Structure of ω-Cyclohexylalkylammonium-[Ni(dmit)2]− Salts

Abstract A previously reported odd-even effect is found to invert by substituting a phenyl with a cyclohexyl group. Crystal structures of [Ni(dmit)2]− complex salts of ω-cyclohexylalkyltrimethylammonium (CncHx; n = 1–5) are revealed by X-ray crystallographic analysis. Alternant stacks are found in all complex salts, but some differences are found in each crystal structure. Terminal cyclohexyl groups adopt chair conformation in the series, and alkylene chains adopt all-trans conformation. Ion pairs found in these crystals are classified by the angle between cations and anions. In these series, odd-even effect is observed in cation length, anion length, Ni-Ni distance and the angle of cation and anion. These are different from the case of terminal methyl and phenyl groups previously reported, indicating that odd-even effect depends on the terminal substituent.

Mechanism and Origins of Stereoinduction in an Asymmetric Friedel-Crafts Alkylation Reaction of Chalcone Catalyzed by Chiral N, N'-Dioxide-Sc(III) Complex.

The mechanism and selectivity of the asymmetric Friedel-Crafts (F-C) alkylation reaction between indole and chalcone catalyzed by chiral N, N'-dioxide-Sc(III) complexes were investigated at the M06/6-311+G(d,p)//M06/[LANL2DZ,6-31G(d)](SMD,CH2Cl2) level. The reaction occurred via a three-step mechanism: (i) the C3-Cβ bond formation by interacting the most mucleophilic C3 center of indole with the most electrophilic Cβ center of chalcone; (ii) the abstraction of the proton at the C3 atom of indole by counterion OTf-; (iii) proton transfer from HOTf to the Cα atom of chalcone, generating the F-C alkylation product. The reaction preferred to occur along the favorable re-face attack pathway, producing the dominant R-product. The turnover frequency (TOF) of catalysis was predicted to be 1.59 × 10-7 s-1, with a rate constant of K( T) = 1.58 × 10-7 exp(-29057/ RT) dm6·mol-2·s-1 over the temperature range of 248-368 K. Activation strain model (ASM) and energy decomposition analysis (EDA), as well as noncovalent interaction (NCI) analysis, for the stereocontrolling transition state revealed that the substituent attached to the N atom of the amide subunits as well as the amino acid backbone of ligand played important roles in chiral inductivity. The benzyl group with structural flexibility tended to form strong π-π stacking with substrate as well as the terminal phenyl group of chalcone, stabilizing re-face attack transition state.

Synthesis and characterization of some novel liquid crystalline compounds of 1,3,4-oxadiazoline and their hydrazone derivatives

ABSTRACTThree new series of mesogens have been synthesized by fixing 4-methoxy or 4-butoxy substituted phenyl ring in one side and 4-hydroxy, bromo or amino substituted phenyl group in the other side with different central linkage. The molecular structure of these series was confirmed by elemental analysis and FTIR and 1HNMR spectroscopy. The mesomorphic properties were studied by using differential scanning calorimetry (DSC) and optical polarizing microscopy (OPM). All the compounds of series [I] exhibit enantiotropic smectic B (SmB) phase. All the compounds of series [II] and [III] display SmB and nematic (N) phases. The mesomorphic properties were found to be dependent on the two terminal 4-substituted phenyl groups and the central linkage group.

Synthesis and In Vitro Antiproliferative Activity of New 1-Phenyl-3-(4-(pyridin-3-yl)phenyl)urea Scaffold-Based Compounds.

A new series of 1-phenyl-3-(4-(pyridin-3-yl)phenyl)urea derivatives were synthesized and subjected to in vitro antiproliferative screening against National Cancer Institute (NCI)-60 human cancer cell lines of nine different cancer types. Fourteen compounds 5a–n were synthesized with three different solvent exposure moieties (4-hydroxylmethylpiperidinyl and trimethoxyphenyloxy and 4-hydroxyethylpiperazine) attached to the core structure. Substituents with different π and σ values were added on the terminal phenyl group. Compounds 5a–e with a 4-hydroxymethylpiperidine moiety showed broad-spectrum antiproliferative activity with higher mean percentage inhibition values over the 60-cell line panel at 10 µM concentration. Compound 5a elicited lethal rather than inhibition effects on SK-MEL-5 melanoma cell line, 786-0, A498, RXF 393 renal cancer cell lines, and MDA-MB-468 breast cancer cell line. Two compounds, 5a and 5d showed promising mean growth inhibitions and thus were further tested at five-dose mode to determine median inhibitory concentration (IC50) values. The data revealed that urea compounds 5a and 5d are the most active derivatives, with significant efficacies and superior potencies than paclitaxel in 21 different cancer cell lines belonging particularly to renal cancer and melanoma cell lines. Moreover, 5a and 5d had superior potencies than gefitinib in 38 and 34 cancer cell lines, respectively, particularly colon cancer, breast cancer and melanoma cell lines.

Extraction Properties of Oligoethylene Glycol Bis[(2-Diphenylphosphinylmethyl-4-methyl)phenyl] Ethers

Extraction of Ln(III), Sc(III), Ga(III), and Re(VII) ions by solutions of phosphorylated monopodands having [ortho-(diphenylphosphinylmethyl)-para-methyl]phenyl terminal groups, 2-Ph2P(O)CH2(4-Me)C6H3(OCH2CH2) n OC6H3(Me-4)CH2P(O)Ph2-2 (n = 1–5), in organic solvents has been studied. The stoichiometries of extractable complexes were determined. The effect of the aqueous phase, organic solvent, and phosphorylated podand structure on the efficacy of metal-ion recovery into organic phase has been considered.

Contiguous multiple π-coordination of π-conjugated polyenes: bonding nature and charge delocalization behaviour of polyene-(palladium chain) sandwich clusters.

The contiguous multiple π-coordination (CMπC) bonds are formed at the molecular interface between the extended π-conjugated sp2-carbon framework and metal-metal moieties. However, the static properties including the bonding nature of the CMπC bonds have not been well-understood. Here we report the charge delocalization behavior and bonding nature of the polyene-(palladium chain) sandwich clusters. We observed the chain-length dependent 13C NMR chemical shifts of the terminal phenyl groups in [Pdm{Ph(CH[double bond, length as m-dash]CH)m+1Ph}2][B(ArF)4]2 (m = 3, 4, 5, 6), showing the efficient delocalization of positive charge over the polyene ligands. Furthermore, the detailed molecular orbital analysis of several model clusters provides insights into the bonding nature of the μ-η2:(η2:)nη2- and μ-η3:(η2:)nη3-poylene palladium chain sandwich clusters, where the former type is attributed to the corner-sharing Pd array and the latter to the edge-sharing/corner-sharing hybrid Pd array. The analogy of the μ-η3:(η2:)nη3-type with the carbonyl-bridge coordination is discussed. The Pd string in each mode of sandwich chain clusters has a weak M-M bonding interaction.

4-Aminoquinoline Antimalarials Containing a Benzylmethylpyridylmethylamine Group Are Active against Drug Resistant Plasmodium falciparum and Exhibit Oral Activity in Mice.

Emergence of drug resistant Plasmodium falciparum including artemisinin-tolerant parasites highlights the need for new antimalarials. We have previously shown that dibemequines, 4-amino-7-chloroquinolines with dibenzylmethylamine (dibemethin) side chains, are efficacious. In this study, analogues in which the terminal phenyl group of the dibemethin was replaced with a 2-pyridyl group and in which the 4-amino-7-chloroquinoline was either maintained or replaced with a 4-aminoquinoline-7-carbonitrile were synthesized in an effort to improve druglikeness. These compounds exhibited significantly improved solubility and decreased lipophilicity and were potent against chloroquine-sensitive (NF54) and -resistant (Dd2 and 7G8) P. falciparum strains with 5/6 having IC50 < 100 nM against the NF54 strain. All inhibited both β-hematin (synthetic hemozoin) formation and hemozoin formation in the parasite. Parasitemia was reduced by over 90% in P. berghei infected mice in 3/6 derivatives following oral dosing at 4 × 30 mg/kg, with microsomal metabolic stability data suggesting that this could be attributed to highly active metabolites.

Substituent Effect on Intramolecular Charge Transfer of Symmetric Methoxy-Substituted Bi-1,3,4-oxadiazole Derivatives.

Intramolecular charge-transfer characteristics of a series symmetric methoxy -substituted bi-1,3,4-oxadiazole derivatives with various substituted positions and quantities have been studied with a combination of experimental techniques and theoretical calculations to investigate the substituent effect. Different degrees of fluorescence red shift in polar solvents are observed in these compounds. The meta-substituted molecule (BOXD-m-OCH3) exhibits a larger red shift (82 nm) than the other two monosubstituted molecules, BOXD-o-OCH3 (40 nm) and BOXD-p-OCH3 (37 nm); the polysubstituted molecules BOXD-D1 and BOXD-T1 show 80 and 104 nm red shifts, respectively, which are obviously larger than the monosubstituted molecules. The changes of molecular dipole moment between the ground state and charge transfer (CT) excited state are calculated to be on the same order with the degree of red shift (7.56 D in BOXD-o-OCH3, 12.07 D in BOXD-m-OCH3, 7.38 D in BOXD-p-OCH3, 14.79 D in BOXD-D1, and 16.80 D in BOXD-T1). Theoretical calculations at the density functional theory level reveal that the first singlet excited state of all of these compounds shows both π-π* and CT characteristics and the charge has been proven to transfer from the terminal methoxy phenyl group to the central bioxadiazole group. The analysis of charge transfer based on electron density shows that the greater the amount substituent, the more charge would be involved in the intramolecular charge transfer. In addition, the negative barycenter has a tendency to locate close to the methoxy substituent, which would cause the difference in the charge-transferred distance. The transferred charge and CT distance work jointly and finally lead to differences in dipole moment variation. These findings could provide very good guidance for the design of molecules with intramolecular charge-transfer characteristics.

Covalently Assembled Monolayers of Homo- and Heteroleptic FeII -Terpyridyl Complexes on SiOx and ITO-Coated Glass Substrates: An Experimental and Theoretical Study.

Well-defined FeII -terpyridyl monolayers were fabricated on SiOx and conductive ITO-coated glass substrates through covalent-bond formation between the metallo-organic complexes and a preassembled coupling layer. Three different homo- and heteroleptic complexes with terminal pyridyl, amine, and phenyl groups were tested. All the films were found to be densely packed and homogeneous, and consist of molecules standing upright. They exhibited high thermal (up to ≈220 °C) and temporal (up to 5 h at 100 °C) stability. The UV/Vis spectra of the monolayers showed pronounced metal-to-ligand charge-transfer bands with a significant redshift compared with the solution spectra of the metallo-ligands with a pendant pyridyl group quaternized with the coupling layer, whereas the shift was significantly smaller when the coupling layer was bonded to the primary amine (-NH2 ) group of the complex. Cyclic voltammograms of the monolayers showed reversible, one-electron redox behavior and suggested strong electronic coupling between the confined molecules and the underlying substrate. Analysis of the electrochemistry data allowed us to estimate the charge-transfer rate constant between the metal center and the substrate. Additionally, detailed quantum-chemical calculations were performed to support and rationalize the experimentally observed photophysical properties of the FeII -terpyridyl complexes both in the solution state and when bound to a SiOx -based substrate.