Nanochannels: hosts for the supramolecular organization of molecules and complexes

Bioactive Luminescent Silver Clusters Confined in Zeolites Enable Quick and Wash-Free Biosensing

The simultaneous capture and detection of biomolecules is crucial for revolutionizing bioanalytical platforms in terms of portability, response time and cost-efficiency. Herein, we demonstrate how the sensitivity to external stimuli and changes in the local electronic environment of silver clusters lead to an advantageous biosensing platform based on the fluorometric response of bioactive luminescent silver clusters (BioLuSiC) confined in faujasite X zeolites functionalized with antibodies. The photoluminescence response of BioLuSiC was enhanced upon immunocomplex formation, empowering a wash-free and quick biodetection system offering optimal results from 5 min. Proteins and pathogens (immunoglobulin G and Escherichia coli) were targeted to demonstrate the biosensing performance of BioLuSiC, and a human serum titration assay was also established. BioLuSiC will pave the way for innovative bioanalytical platforms, including real-time monitoring systems, point-of-care devices and bioimaging techniques.

Catalytic confinement effects in nanochannels: from biological synthesis to chemical engineering

Catalytic reactions within nanochannels are of significant importance in disclosing the mechanisms of catalytic confinement effects and developing novel reaction systems for scientific and industrial demands. Interestingly, catalytic confinement effects exist in both biological and artificial nanochannels, which enhance the reaction performance of various chemical reactions. In this minireview, we investigate the recent advances on catalytic confinement effects in terms of the reactants, reaction processes, catalysts, and products in nanochannels. A systematic discussion of catalytic confinement effects associated with biological synthesis in bio-nanochannels and catalytic reactions in artificial nanochannels in chemical engineering is presented. Furthermore, we summarize the properties of reactions both in nature and chemical engineering and provide a brief overlook of this research field.

Determining the structure of zeolite frameworks at high pressures

The study of porous materials under high-pressure conditions is crucial for the understanding and development of structure–property relationships.

Structural Characterization and Comparison of Monovalent Cation-Exchanged Zeolite-W

We report comparative structural changes of potassium-contained zeolite-W (K-MER, structural analogue of natural zeolite merlinoite) and monovalent extra-framework cation (EFC)-exchanged M-MERs (M = Li⁺, Na⁺, Ag⁺, and Rb⁺). High-resolution synchrotron X-ray powder diffraction study precisely determines that crystal symmetry of MERs is tetragonal (I4/mmm). Rietveld refinement results reveal that frameworks of all MERs are geometrically composed of disordered Al/Si tetrahedra, bridged by linkage oxygen atoms. We observe a structural relationship between a group of Li-, Na-, and Ag-MER and the group of K- and Rb-MER by EFC radius and position of M(1) site inside double 8-membered ring unit (d8r). In the former group, a-axes decrease reciprocally, c-axes gradually extend by EFC size, and M(1) cations are located at the middle of the d8r. In the latter group, a- and c-axes lengths become longer and shorter, respectively, than axes of the former group, and these axial changes come from middle-to-edge migration of M(1) cations inside the d8r channel. Unit cell volumes of the Na-, Ag-, and K-MER are ca. 2005 ų, and the volume expansion in the MER series is limited by EFC size, the number of water molecules, and the distribution of extra-framework species inside the MER channel. EFC sites of M(1) and M(2) show disordered and ordered distribution in the former group, and all EFC sites change to disordered distribution after migration of the M(1) site in the latter group. The amount of water molecules and porosities are inversely proportional to EFC size due to the limitation of volume expansion of MERs. The channel opening area of a pau composite building unit and the amount of water molecules are universally related as a function of cation size because water molecules are mainly distributed inside a pau channel.

Confining a Protein-Containing Water Nanodroplet inside Silica Nanochannels

Incorporation of biological systems in water nanodroplets has recently emerged as a new frontier to investigate structural changes of biomolecules, with perspective applications in ultra-fast drug delivery. We report on the molecular dynamics of the digestive protein Pepsin subjected to a double confinement. The double confinement stemmed from embedding the protein inside a water nanodroplet, which in turn was caged in a nanochannel mimicking the mesoporous silica SBA-15. The nano-bio-droplet, whose size fits with the pore diameter, behaved differently depending on the protonation state of the pore surface silanols. Neutral channel sections allowed for the droplet to flow, while deprotonated sections acted as anchoring piers for the droplet. Inside the droplet, the protein, not directly bonded to the surface, showed a behavior similar to that reported for bulk water solutions, indicating that double confinement should not alter its catalytic activity. Our results suggest that nanobiodroplets, recently fabricated in volatile environments, can be encapsulated and stored in mesoporous silicas.

Water in zeolite L and its MOF mimic

Confinement of molecules in one dimensional arrays of channel-shaped cavities has led to technologically interesting materials. However, the interactions governing the supramolecular aggregates still remain obscure, even for the most common guest molecule: water. Herein, we use computational chemistry methods (#compchem) to study the water organization inside two different channel-type environments: zeolite L – a widely used matrix for inclusion of dye molecules, and ZLMOF – the closest metal-organic-framework mimic of zeolite L. In ZLMOF, the methyl groups of the ligands protrude inside the channels, creating nearly isolated nanocavities. These cavities host well-separated ring-shaped clusters of water molecules, dominated mainly by water-water hydrogen bonds. ZLMOF provides arrays of “isolated supramolecule” environments, which might be exploited for the individual confinement of small species with interesting optical or catalytic properties. In contrast, the one dimensional channels of zeolite L contain a continuous supramolecular structure, governed by the water interactions with potassium cations and by water-water hydrogen bonds. Water imparts a significant energetic stabilization to both materials, which increases with the water content in ZLMOF and follows the opposite trend in zeolite L. The water network in zeolite L contains an intriguing hypercoordinated structure, where a water molecule is surrounded by five strong hydrogen bonds. Such a structure, here described for the first time in zeolites, can be considered as a water pre-dissociation complex and might explain the experimentally detected high proton activity in zeolite L nanochannels.

Adsorption of anthracene substitutes into suprachannels: bulk vs. included guests

Investigation of FRET of included anthracene substitutes within unusual hydrophobic suprachannels was carried out.

Entropy in multiple equilibria, compounds with different sites

The influence of entropy in multiple chemical equilibria is investigated for systems with different types of sites for the condition that the binding enthalpy of the species is the same within each type of sites and independent of those species that are already bonded. This allows splitting of the free reaction enthalpy into the particle distribution term and all other contributions for each type of sites separately and, hence, to evaluate this entropy contribution to the free reaction enthalpy. The situations for which this applies can be chemically very different, e.g. acid base, ligand exchange, isomerisation, conformational change, rearrangement of a ligand, ion exchange, adsorption of a species on the surface of a particle or a dendrimer, insertion of charged or neutral species into the cavities of a microporous or mesoporous host. We provide physical insight by discussing Xrc1{n1ABn2}Xrc2 systems. The number of coordination sites A and B are n1 and n2, respectively. The indices rc1 = 1, 2,…,n1 and rc2 = 1, 2,…,n2 count the number of X bonded to sites A and sites B, respectively. An important result is that the large number of equilibrium constants needed to describe those situations can be expressed as a function of two constants only. This allows studying systems quantitatively by experimental and theoretical means which otherwise might be difficult to handle. It has also implication for theoretical studies in the sense that it is sufficient to model only two reactions instead of many in order to describe a system. The results remain valid for systems with more than two types of different sites. The description of the entropy driven development of the fractional equilibrium coverage of the sites provides a new tool for understanding adsorption and ion exchange isotherms. The fractional equilibrium coverage of the sites can be described as a linear combination of individual Langmuir isotherms despite of the fact that such a linear combination has never the shape of the original Langmuir isotherm. This is remarkable and very useful. It provides us with new tools for describing and testing isotherms based on well defined, transparent physical ideas. Explicit solution for systems with 2, 3, 4, 5, 6, and 12 coordination sites are reported. Applications to a system with 12 coordination sites serve to illustrate information that can be obtained for complex situations.

Supramolecular Organization in Confined Nanospaces

Empty spaces are abhorred by nature, which immediately rushes in to fill the void. Humans have learnt pretty well how to make ordered empty nanocontainers, and to get useful products out of them. When such an order is imparted to molecules, new properties may appear, often yielding advanced applications. This review illustrates how the organized void space inherently present in various materials: zeolites, clathrates, mesoporous silica/organosilica, and metal organic frameworks (MOF), for example, can be exploited to create confined, organized, and self-assembled supramolecular structures of low dimensionality. Features of the confining matrices relevant to organization are presented with special focus on molecular-level aspects. Selected examples of confined supramolecular assemblies - from small molecules to quantum dots or luminescent species - are aimed to show the complexity and potential of this approach. Natural confinement (minerals) and hyperconfinement (high pressure) provide further opportunities to understand and master the atomistic-level interactions governing supramolecular organization under nanospace restrictions.

One-Directional Antenna Systems: Energy Transfer from Monomers to J-Aggregates within 1D Nanoporous Aluminophosphates

A cyanine dye (PIC) was occluded into two 1D-nanopoporus Mg-containing aluminophosphates with different pore size (MgAPO-5 and MgAPO-36 with AFI and ATS zeolitic structure types, with cylindrical channels of 7.3 Å diameter and elliptical channels of 6.7 Å × 7.5 Å, respectively) by crystallization inclusion method. Different J-aggregates are photophysically characterized as a consequence of the different pore size of the MgAPO frameworks, with emission bands at 565 nm and at 610 nm in MgAPO-5 and MgAPO-36, respectively. Computational results indicate a more linear geometry of the J-aggregates inside the nanochannels of the MgAPO-36 sample than those in MgAPO-5, which is as a consequence of the more constrained environment in the former. For the same reason, the fluorescence of the PIC monomers at 550 nm is also activated within the MgAPO-36 channels. Owing to the strategic distribution of the fluorescent PIC species in MgAPO-36 crystals (monomers at one edge and J-aggregates with intriguing emission properties at the other edge) an efficient and one-directional antenna system is obtained. The unidirectional energy transfer process from monomers to J-aggregates is demonstrated by remote excitation experiments along tens of microns of distance.

Self-assembly of a redox-active bolaamphiphile into supramolecular vesicles

Self-assembly of a redox-active bolaamphiphile leads to the formation of narrow-bandgap supramolecular vesicles.

Photochemistry and Photophysics in Silica-Based Materials: Ultrafast and Single Molecule Spectroscopy Observation

Silica-based materials (SBMs) are widely used in catalysis, photonics, and drug delivery. Their pores and cavities act as hosts of diverse guests ranging from classical dyes to drugs and quantum dots, allowing changes in the photochemical behavior of the confined guests. The heterogeneity of the guest populations as well as the confinement provided by these hosts affect the behavior of the formed hybrid materials. As a consequence, the observed reaction dynamics becomes significantly different and complex. Studying their photobehavior requires advanced laser-based spectroscopy and microscopy techniques as well as computational methods. Thanks to the development of ultrafast (spectroscopy and imaging) tools, we are witnessing an increasing interest of the scientific community to explore the intimate photobehavior of these composites. Here, we review the recent theoretical and ultrafast experimental studies of their photodynamics and discuss the results in comparison to those in homogeneous media. The discussion of the confined dynamics includes solvation and intra- and intermolecular proton-, electron-, and energy transfer events of the guest within the SBMs. Several examples of applications in photocatalysis, (photo)sensors, photonics, photovoltaics, and drug delivery demonstrate the vast potential of the SBMs in modern science and technology.

Probing Zeolite Crystal Architecture and Structural Imperfections using Differently Sized Fluorescent Organic Probe Molecules

A micro‐spectroscopic method has been developed to probe the accessibility of zeolite crystals using a series of fluorescent 4‐(4‐diethylaminostyryl)‐1‐methylpyridinium iodide (DAMPI) probes of increasing molecular size. Staining large zeolite crystals with MFI (ZSM‐5) topology and subsequent mapping of the resulting fluorescence using confocal fluorescence microscopy reveal differences in structural integrity: the 90° intergrowth sections of MFI crystals are prone to develop structural imperfections, which act as entrance routes for the probes into the zeolite crystal. Polarization‐dependent measurements provide evidence for the probe molecule's alignment within the MFI zeolite pore system. The developed method was extended to BEA (Beta) crystals, showing that the previously observed hourglass pattern is a general feature of BEA crystals with this morphology. Furthermore, the probes can accurately identify at which crystal faces of BEA straight or sinusoidal pores open to the surface. The results show this method can spatially resolve the architecture‐dependent internal pore structure of microporous materials, which is difficult to assess using other characterization techniques such as X‐ray diffraction.

Photoactive Nanomaterials Inspired by Nature: LTL Zeolite Doped with Laser Dyes as Artificial Light Harvesting Systems

The herein reported work describes the development of hierarchically-organized fluorescent nanomaterials inspired by plant antenna systems. These hybrid materials are based on nanostructured zeolitic materials (LTL zeolite) doped with laser dyes, which implies a synergism between organic and inorganic moieties. The non-interconnected channeled structure and pore dimensions (7.1 Å) of the inorganic host are ideal to order and align the allocated fluorophores inside, inferring also high thermal and chemical stability. These artificial antennae harvest a broad range of chromatic radiation and convert it into predominant red-edge or alternatively white-light emission, just choosing the right dye combination and concentration ratio to modulate the efficiency of the ongoing energy transfer hops. A further degree of organization can be achieved by functionalizing the channel entrances of LTL zeolite with specific tailor-made (stopcock) molecules via a covalent linkage. These molecules plug the channels to avoid the leakage of the guest molecules absorbed inside, as well as connect the inner space of the zeolite with the outside thanks to energy transfer processes, making the coupling of the material with external devices easier.

Irreversible Conversion of a Water-Ethanol Solution into an Organized Two-Dimensional Network of Alternating Supramolecular Units in a Hydrophobic Zeolite under Pressure

Turning disorder into organization is a key issue in science. By making use of X-ray powder diffraction and modeling studies, we show herein that high pressures in combination with the shape and space constraints of the hydrophobic all-silica zeolite ferrierite separate an ethanol-water liquid mixture into ethanol dimer wires and water tetramer squares. The confined supramolecular blocks alternate in a binary two-dimensional (2D) architecture that remains stable upon complete pressure release. These results support the combined use of high pressures and porous networks as a viable strategy for driving the organization of molecules or nano-objects towards complex, pre-defined patterns relevant for the realization of novel functional nanocomposites.

Entropy in multiple equilibria, theory and applications

Entropy controls the dependence of the equilibrium constants in the synthesis of host–guest composites on the occupation rc for channels of different length.

Recent Advances in Various Metal-Organic Channels for Photochemistry beyond Confined Spaces

Tailor-made molecular channel architectures are a hot issue in the fields of nanotechnology, molecular sieves, ion sensors, recognition, confined space reactors, and fluidic transport systems. Carbon nanotubes have been a particular focus, though they cannot easily be synthesized to predefined structures and sizes. Rational design and construction of molecular channel structures based on coordination chemistry has been recognized as a useful approach. Metal-organic channel (MOC) structures can be generated by utilizing, at least in principle, molecular self-assembly of metal ions as angular units with designed ligands as spacers. Recent developments in molecular channel chemistry include exciting advances in photochemical applications and supramolecular material functionality, in addition to general applications such as transport, diffusion and exchange, separation, gas storage, catalysis, and simple encapsulation. In order to carry out the diverse channel functionalities, a large number of studies have been conducted on the synthesis of robust and stable 3D coordination polymers, which show permanent porosity without any guest molecules within the channels, in that the robustness of the channel structures after removal of the solvate/guest molecules is of interest because the structural integrity of the extended structures must be maintained during the reactions. These compounds can be regarded as analogous to zeolites. This Account highlights advances in the construction, from metal cations and multidentate pyridyl ligands, of various MOCs and useful molecular materials as photoreaction platforms. We begin by discussing the fact that detailed proof-of-concept construction of various systematic MOC structures has been introduced mainly in terms of the metal ions as angular components and the pyridyl ligands as spacers. This approach leads to structural complexity of assembled MOC motifs such as metallamacrocycles, helical and cylindrical coordination polymers, vertical arrays of 1D coordination polymers, interweaving and eclipsed stacking of 2D coordination polymers, and typical 3D coordination polymers. Notwithstanding the diversity of their skeletal structures, confined spaces of the channels are suitable for the study of photochemical performances including radical trapping, photocyclopropanation, dye inclusion and energy transfer, and guest-to-host structural transmission. The key aspect of their utility is not only the preparation of photoresistant MOCs but also channel tuning for inclusion of photoactive guests. Guest molecules, which are compatible with the size, shape, and polarity of the channels, can be incorporated into the crystals, instead of simple organic solvents, thus giving rise to host-guest complexes in the solid state. Such MOC studies could facilitate the development of chemical sensors, new photocatalytic systems, and useful molecular photochemical reactors.

Light-Harvesting Antennae Based on Silicon Nanocrystals

Silicon (Si) nanocrystals are relatively strong light emitters, but are weak light absorbers as a result of their indirect band gap. One way to enhance light absorption is to functionalize the nanocrystals with chromophores that are strong light absorbers. By designing systems that enable efficient energy transfer from the chromophore to the Si nanocrystal, the brightness of the nanocrystals can be significantly increased. There have now been a few experimental systems in which covalent attachment of chromophores, efficient energy transfer and significantly increased brightness have been demonstrated. This review discusses progress on these systems and the remaining challenges.

Light-harvesting antennae based on photoactive silicon nanocrystals functionalized with porphyrin chromophores

Silicon nanocrystals functionalized with tetraphenylporphyrin Zn(II) chromophores at the periphery perform as light harvesting antennae: excitation of the porphyrin units in the visible spectral region yields sensitized emission of the silicon nanocrystal core in the near infrared with a long lifetime (λ(max) = 905 nm, τ = 130 μs). This result demonstrates that this hybrid material has a potential application as a luminescent probe for bioimaging.

Optical assembly of bio-hybrid micro-robots

The combination of micro synthetic structures with bacterial flagella motors represents an actual trend for the construction of self-propelled micro-robots. The development of methods for fabrication of these bacteria-based robots is a first crucial step towards the realization of functional miniature and autonomous moving robots. We present a novel scheme based on optical trapping to fabricate living micro-robots. By using holographic optical tweezers that allow three-dimensional manipulation in real time, we are able to arrange the building blocks that constitute the micro-robot in a defined way. We demonstrate exemplarily that our method enables the controlled assembly of living micro-robots consisting of a rod-shaped prokaryotic bacterium and a single elongated zeolite L crystal, which are used as model of the biological and abiotic components, respectively. We present different proof-of-principle approaches for the site-selective attachment of the bacteria on the particle surface. The propulsion of the optically assembled micro-robot demonstrates the potential of the proposed method as a powerful strategy for the fabrication of bio-hybrid micro-robots.

Photoreaction of adsorbed diiodomethane: halide effects of a series of neutral palladium(ii) coordination cages

The synthetic aspect of a series of [Pd₆X₁₂L₄] (X⁻ = Cl⁻, Br⁻, I⁻) cages, including Br/I replacement reaction and halide effects on physicochemical properties, adsorption of CH₂I₂, and photo-cyclopropanation, has been investigated.

Crystalline capsules: metal-organic frameworks locked by size-matching ligand bolts

Metal-organic frameworks (MOFs) are shown to be good examples of a new class of crystalline porous materials for guest encapsulation. Since the encapsulation/release of guest molecules in MOF hosts is a reversible process in nature, how to prevent the leaching of guests from the open pores with minimal and nondestructive modifications of the structure is a critical issue. To address this issue, we herein propose a novel strategy of encapsulating guests by introducing size-matching organic ligands as bolts to lock the pores of the MOFs through deliberately anchoring onto the open metal sites in the pores. Our proposed strategy provides a mechanical way to prevent the leaching of guests and thereby has less dependence on the specific chemical environment of the hosts, thus making it applicable for a wide variety of existing MOFs once the size-matching ligands are employed.

Remarkable stimulation of emission quenching on a clay surface

Tetra-cationic pyrene derivative (Py(4+)) and tris(bipyridine)ruthenium(II) (Ru(2+)) were hybridized onto the surface of a synthesized clay. We observed the remarkable stimulation of excited Py(4+) emission quenching on the clay surface, with a very large apparent quenching rate constant (kq = 7.4 ± 0.7 × 10(15) L mol(-1) s(-1)).

Artificial light-harvesting arrays for solar energy conversion

Following natures' blueprint, the concept of artificial light-harvesting antennae is discussed in terms of sophisticated molecular arrays displaying a tailored cascade of electronic energy transfer steps.

Synthesis and photo-postmodification of zeolite L based polymer brushes

Zeolite L macroinitiators are used for controlled radical copolymerization of a photo-active monomer and subsequent spin trapping of nitroxides results in diversely functionalized particles.

Photoactive amphiphiles for the assembly of supramolecular architectures

The presented study reports the use of photoactive templating structures for the design of porous frameworks with built-in optical functionalities. The materials have been synthesised and characterised using powder X-ray diffractometry, UV-visible absorption and emission spectroscopy. The latter shows that, by varying the relative amount of an amphiphilic chromophore in the micellar templates, it is possible to tune the light absorption and emission properties over the visible spectrum, by means of controlling the molecular organisation and the excitonic coupling of aggregated species. This enables versatile solid materials that can be used as optical components for light-harvesting and converting systems to be obtained .

Luminescent hybrid materials based on zeolite L crystals and lanthanide complexes: host-guest assembly and ultraviolet-visible excitation

Several kinds of host-guest hybrid materials have been synthesized employing a ship in a bottle method by loading 9-hydroxy-2-methylphenalenone (MHPO) or 9-hydroxyphenalen (HPNP) from gas phase into the nanochannels of Ln(3+)-exchanged zeolite L (ZL) crystals (Ln=Gd or Eu). The resulting hybrids without lanthanide ions, MHPO-ZL, HPNP-ZL and the hybrids with lanthanide ions Ln-MHPO-ZL and Ln-HPNP-ZL are characterized with FT-IR, UV-vis DRS and photoluminescence spectroscopy. The photoluminescence properties of these hybrid materials have been analyzed and discussed, exhibiting the luminescence of Eu(3+) and ligands under the excitation at ultraviolet-visible region. These results provide useful data and can be expected to have potential application in the practical fields.

Preparation, photophysical characterization, and modeling of LDS722/Laponite 2D-ordered hybrid films

A novel hybrid material with promising optical properties for nonlinear optical applications is presented, as formed by LDS 722 organic dye confined in Laponite clay. Thin films of the hybrid material with different dye loadings have been prepared. The film thickness, the dye and water content, and the clay swelling due to guest molecule incorporation have been characterized. Then, the photophysical properties of the thin films have been studied in detail using experimental methods and molecular simulation. As the dye load increases, the hybrid films present a hypsochromic shift in absorption and a bathochromic shift in emission. The former is attributed to the increasing strength of solvation of the dye donor group, while the latter is ascribed to a switch from an intramolecular to an intermolecular charge-transfer process as the dye load increases. The LDS 722 molecules are preferentially oriented in the host clay almost in parallel to the platelet surfaces, inducing macroscopic order that makes the material responsive to polarized light.

Light-harvesting photocatalysis for water oxidation using mesoporous organosilica

An organic-based photocatalysis system for water oxidation, with visible-light harvesting antennae, was constructed using periodic mesoporous organosilica (PMO). PMO containing acridone groups in the framework (Acd-PMO), a visible-light harvesting antenna, was supported with [Ru(II)(bpy)3(2+)] complex (bpy = 2,2'-bipyridyl) coupled with iridium oxide (IrO(x)) particles in the mesochannels as photosensitizer and catalyst, respectively. Acd-PMO absorbed visible light and funneled the light energy into the Ru complex in the mesochannels through excitation energy transfer. The excited state of Ru complex is oxidatively quenched by a sacrificial oxidant (Na2S2O8) to form Ru(3+) species. The Ru(3+) species extracts an electron from IrO(x) to oxidize water for oxygen production. The reaction quantum yield was 0.34 %, which was improved to 0.68 or 1.2 % by the modifications of PMO. A unique sequence of reactions mimicking natural photosystem II, 1) light-harvesting, 2) charge separation, and 3) oxygen generation, were realized for the first time by using the light-harvesting PMO.

Spatially controlled channel entrances functionalization of zeolites L

The spatially controlled channel entrances functionalization of disk shaped zeolite L crystals is described. Fluorescent dye or bioactive molecules are immobilized at one end of the channels of zeolite crystals and subsequently the other side of the crystals is derivatized with magnetic iron oxide nanoparticles. The asymmetrically functionalized crystals were used for the control of the movement of bacteria in solution.

Hybridization between periodic mesoporous organosilica and a Ru(II) polypyridyl complex with phosphonic acid anchor groups

A new method for the hybridization of a ruthenium(II) polypyridyl complex ([Ru(bpy)2((CH2PO3H2)2-bpy)](2+) (RuP2(2+): bpy =2,2'-bipyridine; (CH2PO3H2)2-bpy =2,2'-bipyridine-4,4'di(metylphosphonic acid)) with biphenylene-bearing periodic mesoporous organosilica (Bp-PMO made from 4,4'bis(triethoxysilyl)biphenyl [(C2H5O)3Si-(C6H4)2-Si(OC2H5)3]) was developed. Efficient and secure fixation of the ruthenium(II) complex with methylphosphonic acid groups (RuP2(2+)) in the mesopores of Bp-PMO occurred. This method introduced up to 660 μmol of RuP2(2+) in 1 g of Bp-PMO. Two modes of adsorption of RuP2(2+) in the mesopores of Bp-PMO were observed: one is caused by the chemical interaction between the methylphosphonic acid groups of RuP2(2+) and the silicate moieties of Bp-PMO and the other is attributed to aggregation of the RuP2(2+) complexes. In the case of the former mode, adsorbed RuP2(2+) (up to 80-100 μmol g(-1)) did not detach from Bp-PMO after washing with acetonitrile, dimethylformamide, or even water. Emission from the excited biphenylene (Bp) units was quantitatively quenched by the adsorbed RuP2(2+) molecules in cases where more than 60 μmol g(-1) of RuP2(2+) was adsorbed, and emission from RuP2(2+) was observed. Quantitative emission measurements indicated that emission from approximately 100 Bp units can be completely quenched by only one RuP2(2+) molecule in the mesopore, and photons absorbed by approximately 400 Bp units are potentially accumulated in one RuP2(2+) molecule.