Development of Pd/In2O3 hybrid nanoclusters to optimize ethanol vapor sensing.

In this study, we successfully synthesize palladium-decorated indium trioxide (Pd/In2O3) hybrid nanoclusters (NCs) using an advanced dual-target cluster beam deposition (CBD) method, a significant stride in developing high-performance ethanol sensors. The prepared Pd/In2O3 hybrid NCs exhibit exceptional sensitivity, stability, and selectivity to low concentrations of ethanol vapor, with a maximum response value of 101.2 at an optimal operating temperature of 260 °C for 6 at% Pd loading. The dynamic response of the Pd/In2O3-based sensor shows an increase in response with increasing ethanol vapor concentrations within the range of 50 to 1000 ppm. The limit of detection is as low as 24 ppb. The sensor exhibits a high sensitivity of 28.24 ppm-1/2, with response and recovery times of 2.7 and 4.4 seconds, respectively, for 100 ppm ethanol vapor. Additionally, the sensor demonstrates excellent repeatability and stability, with only a minor decrease in response observed over 30 days and notable selectivity for ethanol compared to other common volatile organic compounds. The study highlights the potential of Pd/In2O3 NCs as promising materials for ethanol gas sensors, leveraging the unique capabilities of CBD for controlled synthesis and the catalytic properties of Pd for enhanced gas-sensing performance.

Antibacterial oxygenated ergostane-type steroids produced by the marine sponge-derived fungus Aspergillus sp.

Two oxygenated ergostane-type steroids including one new compound, 3ß-hydroxy-5α,6ß-methoxyergosta-7,22-dien-15-one (1) along with a known analogue ergosta-6,22-dien-3ß,5α,8α-triol (2) were isolated from the crude extracts of the marine sponge-derived fungus Aspergillus sp. Their structures were elucidated on the basis of combined NMR and MS spectroscopic methods. Compound 1 was a marine ergostane-type steroid with two methoxy groups at C-5 and C-6, respectively. These oxygenated ergostane-type steroids were evaluated for their antibacterial activities against human or aquatic pathogens. Among them, compound 1 exhibited antibacterial activity against Staphylococcus aureus.

Construction of Negative Electrostatic Pore Environments in a Scalable, Stable and Low-Cost Metal-organic Framework for One-Step Ethylene Purification from Ternary Mixtures.

One-step separation of C2 H4 from ternary C2 mixtures by physisorbents remains a challenge to combine excellent separation performance with high stability, low cost, and easy scalability for industrial applications. Herein, we report a strategy of constructing negative electrostatic pore environments in a stable, low-cost, and easily scaled-up aluminum MOF (MOF-303) for efficient one-step C2 H2 /C2 H6 /C2 H4 separation. This material exhibits not only record high C2 H2 and C2 H6 uptakes, but also top-tier C2 H2 /C2 H4 and C2 H6 /C2 H4 selectivities at ambient conditions. Theoretical calculations combined with in situ infrared spectroscopy indicate that multiple N/O sites on pore channels can build a negative electro-environment to provide stronger interactions with C2 H2 and C2 H6 over C2 H4 . Breakthrough experiments confirm its exceptional separation performance for ternary mixtures, affording one of the highest C2 H4 productivity of 1.35 mmol g-1 . This material is highly stable and can be easily synthesized at kilogram-scale from cheap raw materials using a water-based green synthesis. The benchmark combination of excellent separation properties with high stability and low cost in scalable MOF-303 has unlocked its great potential in this challenging industrial separation.

Scalable Green Synthesis of Robust Ultra-Microporous Hofmann Clathrate Material with Record C3 H6 Storage Density for Efficient C3 H6 /C3 H8 Separation.

Developing porous materials for C3 H6 /C3 H8 separation faces the challenge of merging excellent separation performance with high stability and easy scalability of synthesis. Herein, we report a robust Hofmann clathrate material (ZJU-75a), featuring high-density strong binding sites to achieve all the above requirements. ZJU-75a adsorbs large amount of C3 H6 with a record high storage density of 0.818 g mL-1 , and concurrently shows high C3 H6 /C3 H8 selectivity (54.2) at 296 K and 1 bar. Single-crystal structure analysis unveil that the high-density binding sites in ZJU-75a not only provide much stronger interactions with C3 H6 but also enable the dense packing of C3 H6 . Breakthrough experiments on gas mixtures afford both high separation factor of 14.7 and large C3 H6 uptake (2.79 mmol g-1 ). This material is highly stable and can be easily produced at kilogram-scale using a green synthesis method, making it as a benchmark material to address major challenges for industrial C3 H6 /C3 H8 separation.

Metal Nanocluster-Metal Organic Framework-Polymer Hybrid Nanomaterials for Improved Hydrogen Detection.

The development of hydrogen sensors is of paramount importance for timely leak detection and remains a crucial unmet need. Palladium-based materials, well known as hydrogen sensors, still suffer from poisoning and deactivation. Here, a hybrid hydrogen sensor consisting of a Pd nanocluster (NC) film, a metal-organic framework (MOF), and a polymer, are proposed. The polymer coating, as a protection layer, endows the sensor with excellent H2 selectivity and CO-poisoning resistance. The MOF serves as an interface layer between the Pd NC film and the polymer layer, which alters the nature of the interaction with hydrogen and leads to significant sensing performance improvements, owing to the interfacial electronic coupling between Pd NCs and the MOF. The strategy overcomes the shortcomings of retarded response speed and degraded sensitivity induced by the polymer coating of a Pd NC film-polymer hybrid system. This is the first exhibition of a hydrogen-sensing enhancement mechanism achieved by engineering the electronic coupling between Pd and a MOF. The work establishes a deep understanding of the hydrogen-sensing enhancement mechanism at the nanoscale and provides a feasible strategy to engineer next-generation gas-sensing nanodevices with superior sensing figures of merit via hybrid material systems.

Engineering Supramolecular Binding Sites in a Chemically Stable Metal-Organic Framework for Simultaneous High C2 H2 Storage and Separation.

Developing porous materials to overcome the trade-off between adsorption capacity and selectivity for C2 H2 /CO2 separation remains a challenge. Herein, we report a stable HKUST-1-like MOF (ZJU-50a), featuring large cages decorated with high density of supramolecular binding sites to achieve both high C2 H2 storage and selectivity. ZJU-50a exhibits one of the highest C2 H2 storage capacity (192 cm3 g-1 ) and concurrently high C2 H2 /CO2 selectivity (12) at 298 K and 1 bar. Single-crystal X-ray diffraction studies on gas-loaded ZJU-50a crystal unveil that the incorporated supramolecular binding sites can selectively take up C2 H2 molecule but not CO2 to result in both high C2 H2 storage and selectivity. Breakthrough experiments validated its separation performance for C2 H2 /CO2 mixtures, providing a high C2 H2 recovery capacity of 84.2 L kg-1 with 99.5 % purity. This study suggests a novel strategy of engineering supramolecular binding sites into MOFs to overcome the trade-off for this separation.

Compact Magneto-Fluorescent Colloids by Hierarchical Assembly of Dual-Components in Radial Channels for Sensitive Point-of-Care Immunoassay.

Exploring signal amplification strategies to enhance the sensitivity of lateral flow immunoassay (LFIA) is of great significance for point-of-care (POC) testing of low-concentrated targets in the field of in vitro diagnostics. Here, a highly-sensitive LFIA platform using compact and hierarchical magneto-fluorescent assemblies as both target-enrichment substrates and optical sensing labels is demonstrated. The large-pored dendritic templates are utilized for high-density incorporation of both superparamagnetic iron oxide nanoparticles (IOs) and quantum dots (QDs) within the vertical channels. The hierarchical structure is built via affinity-driven assembly of IOs and QDs from organic phase with silica surface and mercapto-organosilica intermediate layer, respectively. The sequential assembly with central-radial channels enables 3D loading of dual components and separately controlling of discrete functionalities. After the alkyl-organosilica encapsulation and silica sealing, the composite spheres exhibit high stabilities and compatibility with LFIA for procalcitonin (PCT) detection. With the assistance of liquid-phase antigen-capturing, magnetic enrichment, and fluorescence-signal amplification, a limit of detection of 0.031 ng mL-1 for PCT is achieved with a linear range from 0.012 to 10 ng mL-1 . The current LFIA is robust and validated for PCT detection in real serum, which holds great diagnostic significance for precise guidance of antibiotic therapy with POC manner.

Dense Packing of Acetylene in a Stable and Low-Cost Metal-Organic Framework for Efficient C2 H2 /CO2 Separation.

Porous materials for C2 H2 /CO2 separation mostly suffer from high regeneration energy, poor stability, or high cost that largely dampen their industrial implementation. A desired adsorbent should have an optimal balance between excellent separation performance, high stability, and low cost. We herein report a stable, low-cost, and easily scaled-up aluminum MOF (CAU-10-H) for highly efficient C2 H2 /CO2 separation. The suitable pore confinement in CAU-10-H can not only provide multipoint binding interactions with C2 H2 but also enable the dense packing of C2 H2 inside the pores. This material exhibits one of the highest C2 H2 storage densities of 392 g L-1 and highly selective adsorption of C2 H2 over CO2 at ambient conditions, achieved by a low C2 H2 adsorption enthalpy (27 kJ mol-1 ). Breakthrough experiments confirm its exceptional separation performance for C2 H2 /CO2 mixtures, affording both large C2 H2 uptake of 3.3 mmol g-1 and high separation factor of 3.4. CAU-10-H achieves the benchmark balance between separation performance, stability, and cost for C2 H2 /CO2 separation.

Selective Ethane/Ethylene Separation in a Robust Microporous Hydrogen-Bonded Organic Framework.

The separation of ethane (C2H6) from ethylene (C2H4) is of prime importance in the production of polymer-grade C2H4 for industrial manufacturing. It is very challenging and still remains unexploited to fully realize efficient C2H6/C2H4 separation in the emerging hydrogen-bonded organic frameworks (HOFs) due to the weak nature of hydrogen bonds. We herein report the benchmark example of a novel ultrarobust HOF adsorbent (termed as HOF-76a) with a Brunauer-Emmett-Teller surface area exceeding 1100 m2 g-1, exhibiting the preferential binding of C2H6 over C2H4 and thus highly selective separation of C2H6/C2H4. Theoretical calculations indicate the key role of the nonpolar surface and the suitable triangular channel-like pores in HOF-76a to sterically "match" better with the nonplanar C2H6 molecule than the planar C2H4, thus affording overall stronger multipoint van der Waals interactions with C2H6. The exceptional separation performance of HOF-76a for C2H6/C2H4 separation was clearly demonstrated by gas adsorption isotherms, ideal adsorbed solution theory calculations, and simulated and experimental breakthrough curves. Breakthrough experiments on HOF-76a reveal that polymer-grade ethylene gas can be straightforwardly produced from 50/50 (v/v) C2H6/C2H4 mixtures during the first adsorption cycle with a high productivity of 7.2 L/kg at 298 K and 1.01 bar and 18.8 L/kg at 298 K and 5.0 bar, respectively.

A Metal-Organic Framework with Suitable Pore Size and Specific Functional Sites for the Removal of Trace Propyne from Propylene.

Separation of propyne/propylene (C3 H4 /C3 H6 ) is more difficult and challenging than that of acetylene/ethylene (C2 H2 /C2 H4 ) because of their closer molecular sizes. A comprehensive screening of a series of metal-organic frameworks with broad types of structures, pore sizes, and functionalities was carried out. UTSA-200 was identified as the best separating material for the removal of trace C3 H4 from C3 H4 /C3 H6 mixtures. Gas sorption isotherms reveal that UTSA-200 exhibits by far the highest C3 H4 adsorption capacity (95 cm3 cm-3 at 0.01 bar and 298 K) and record C3 H4 /C3 H6 selectivity, which was mainly attributed to the suitable dynamic pore size to efficiently block the larger C3 H6 molecule whilst the strong binding sites and pore flexibility capture smaller C3 H4 . This material thus provides record purification capacity for the removal of C3 H4 from a 1:99 (or 0.1:99.9, v/v) C3 H4 /C3 H6 mixture to produce 99.9999 % pure C3 H6 with a productivity of 62.0 (or 142.8) mmol g-1 .

A Microporous Metal-Organic Framework with Lewis Basic Nitrogen Sites for High C2H2 Storage and Significantly Enhanced C2H2/CO2 Separation at Ambient Conditions.

A novel metal-organic framework (MOF), [Cu2L(H2O)2]·7DMF·4H2O [ZJU-40; H4L = 5,5'-(pyrazine-2,5-diyl)diisophthalic acid], with Lewis basic nitrogen sites has been constructed and structurally characterized. Owing to the combined features of high porosity, moderate pore sizes, and immobilized Lewis basic nitrogen sites, the activated ZJU-40a exhibits the second-highest gravimetric C2H2 uptake of 216 cm(3) g(-1) (at 298 K and 1 bar) among all of the reported MOFs so far. This value is not only much higher than that of the isoreticular NOTT-101a (184 cm(3) g(-1)), but also superior to those of two very promising MOFs, known as HKUST-1 (201 cm(3) g(-1)) and Co-MOF-74 (197 cm(3) g(-1)). Interestingly, the immobilized nitrogen sites in ZJU-40a have nearly no effect on the CO2 uptake, so ZJU-40a adsorbs a similar amount of CO2 (87 cm(3) g(-1)) compared with NOTT-101a (84 cm(3) g(-1)) at 298 K and 1 bar. As a result, ZJU-40a shows significantly enhanced adsorption selectivity for C2H2/CO2 separation (17-11.5) at ambient temperature compared to that of NOTT-101a (8-9), leading to a superior MOF material for highly selective C2H2/CO2 separation.

[Entering the Dawn of a New Life: A Discussion of Life for Survivors of the Formosa Fun Coast Water Park Explosion].

A dust explosion at the Formosa Fun Coast water park in Taiwan caused nearly 500 burn injury cases. One hundred of these cases involved burns over more than 20% of the total body surface area. This tragedy inundated hospitals across northern Taiwan with an unprecedented number of burn patients. Significant manpower and medical resources were targeted on related resuscitation and treatment efforts, with support and assistance provided by agencies and organizations nationwide. Most of the burn patients were young people in their teens and twenties, whose severe burns posed the greatest threat and challenge to their lives so far. Furthermore, their experience presented major psychosocial and physical health challenges. Patients received an array of clinical treatments such as debridement, skin grafting, dressing, and rehabilitation. Debilitating pain, skin damage, changes to body image, physical disabilities, helplessness, sadness, and anxiety have not only deeply affected the patients physically and psychologically but also created significant life stresses for their family members / companions, which requires counseling in order to facilitate emotional healing. Although burn patients gradually recover as they pass through the acute, recovery, and rehabilitation phases, they will face the challenges of lifelong rehabilitation after discharge. I hope that these young victims will take courage and be brave and strong in dealing with the difficulties and challenges of daily life and will embrace the future with hope as they enter the dawn of their new life.

Multistate and Multicolor Photochromism through Selective Cycloreversion in Asymmetric Platinum(II) Complexes with Two Different Dithienylethene-Acetylides.

Four asymmetric bis(dithienylethene-acetylide) platinum(II) complexes trans-Pt(PEt3)2(L1o)(L5o) (1oo), trans-Pt(PEt3)2(L2o)(L5o) (2oo), trans-Pt(PEt3)2(L3o)(L5o) (3oo), and trans-Pt(PEt3)2(L4o)(L5o) (4oo) with two different dithienylethene-acetylides (L1o-L5o) were designed to modulate stepwise, multistate, and multicolor photochromism by modifying ring-closure absorption wavelengths. Upon irradiation under UV light, 1oo converts only to 1oc without the observation of 1co and dually ring-closed species 1cc. In contrast, both mixed ring-open/closed species oc and co as well as dually ring-closed species cc are observed upon UV light irradiation of 2oo-4oo, implying that a substantial stepwise photochromic process occurs following 2oo-4oo → 2oc-4oc/2co-4co → 2cc-4cc. The conversion percentage of dually ring-closed species at the photostationary state (PSS) is progressively increased following 1cc (0%) → 2cc (40%) → 3cc (86%) → 4cc (>95%), coinciding with the progressive red-shift of ring-closure absorption bands in free L1c (441 nm) → L2c (510 nm) → L3c (556 nm) → L4c (591 nm). Particularly, compound 2 affords four states (2oo, 2co, 2oc, and 2cc) with different colors (colorless, purple, blue, and dark blue, respectively) through a selective photochemical cycloreversion process upon irradiation with appropriate wavelengths of light. Although stepwise photocyclization reactions 3oo → 3co/3oc → 3cc and 4oo → 4co/4oc → 4cc are observed, multicolor photochromism of 3oo and 4oo could not be achieved because ring-closure absorption bands between L3c/L4c and L5c are significantly overlapped. The stepwise photochemical processes are well demonstrated by NMR, UV-vis, and infrared (IR) spectroscopy and time-dependent density functional theory (TD-DFT) computational studies.

A porous metal-organic framework with dynamic pyrimidine groups exhibiting record high methane storage working capacity.

We have realized a new porous metal-organic framework UTSA-76a with pyrimidine groups on the linker, exhibiting high volumetric methane uptake of ~260 cm(3) (STP) cm(-3) at 298 K and 65 bar, and record high working capacity of ~200 cm(3) (STP) cm(-3) (between 5 and 65 bar). Such exceptionally high working capacity is attributed to the central "dynamic" pyrimidine groups within UTSA-76a, which are capable of adjusting their orientations to optimize the methane packing at high pressure, as revealed by computational studies and neutron scattering experiments.

Innovative Thermocatalytic H2 Sensor with Double-Sided Pd Nanocluster Films on an Ultrathin Mica Substrate.

Hydrogen (H2) is crucial in the future global energy landscape due to its eco-friendly properties, but its flammability requires precise monitoring. This study introduces an innovative thermocatalytic H2 sensor utilizing ultrathin mica sheets as substrates, coated on both sides with Pd nanocluster (NC) films. The ultrathin mica substrate ensures robustness and flexibility, enabling the sensor to withstand high temperatures and mechanical deformation. Additionally, it simplifies the fabrication process by eliminating the need for complex microelectro-mechanical systems (MEMS) technology. Constructed through cluster beam deposition, the sensor exhibits exceptional characteristics, including a wide concentration range (from 500 ppm to 4%), rapid response and recovery times (3.1 and 2.4 s for 1% H2), good selectivity, high stability, and repeatability. The operating temperature can be as low as 40 °C, achieving remarkably low power consumption. The study explores the impact of double-sided versus single-sided catalytic layers, revealing significantly higher sensitivity and response with the double-sided configuration due to the increased catalytic surface area. Additionally, the research investigates the relationship between the deposition amount of Pd NCs and the sensor's sensitivity, identifying an optimal value that maximizes performance without excessive use of Pd. The sensor's innovative design and excellent performance position it as a promising candidate for meeting the demands of a hydrogen-based energy economy.

Modulating stepwise photochromism in platinum(II) complexes with dual dithienylethene-acetylides by a progressive red shift of ring-closure absorption.

To modulate stepwise photochromism by shifting ring-closure absorption of the dithienylethene (DTE) moiety, trans-Pt(PEt3)2(C≡C-DTE)2 [C≡C-DTE = L1o (1oo), L2o (2oo), L3o (3oo), and L4o (4oo)] and cis-Pt(PEt3)2(L4o)2 (5oo) with two identical DTE-acetylides were elaborately designed. With the gradual red shift of ring-closure absorption for L1c (441 nm) → L2c (510 nm) → L3c (556 nm) → L4c (602 nm), stepwise photochromism is increasingly facilitated in trans-Pt(PEt3)2(C≡C-DTE)2 following 1oo → 2oo → 3oo → 4oo. The conversion percentage of singly ring-closed 2co-4co to dually ring-closed 2cc-4cc at the photostationary state is progressively increased in the order 1cc (0%) → 2cc (18%) → 3cc (67%) → 4cc (100%). Compared with trans-arranged 4oo, stepwise photochromism in the corresponding cis-counterpart 5oo is less pronounced, ascribed to either direct conversion of 5oo to 5cc or rapid conversion of 5co to 5cc. The progressively facile stepwise photocyclization following 2oo → 3oo → 4oo is reasonably interpreted by gradually enhanced transition character involving LUMO+1, which is the only unoccupied frontier orbital responsible for further photocyclization of singly ring-closed 2co-4co.

Programmed fluorine binding engineering in anion-pillared metal-organic framework for record trace acetylene capture from ethylene.

Porous physisorbents are attractive candidates for selective capture of trace gas or volatile compounds due to their low energy footprints. However, many physisorbents suffer from insufficient sorbate-sorbent interactions, resulting in low uptake or inadequate selectivity when gases are present at trace levels. Here, we report a strategy of programmed fluorine binding engineering in anion-pillared metal-organic frameworks to maximize C2H2 binding affinity for benchmark trace C2H2 capture from C2H4. A robust material (ZJU-300a) was elaborately designed to provide multiple-site fluorine binding model, resulting in an ultrastrong C2H2 binding affinity. ZJU-300a exhibits a record-high C2H2 uptake of 3.23 millimoles per gram (at 0.01 bar and 296 kelvin) and one of the highest C2H2/C2H4 selectivity (1672). The adsorption binding of C2H2 and C2H4 was visualized by gas-loaded ZJU-300a structures. The separation capacity was confirmed by breakthrough experiments for 1/99 C2H2/C2H4 mixtures, affording the maximal dynamic selectivity (264) and C2H4 productivity of 436.7 millimoles per gram.

Construction of Fluorinated Propane-Trap in Metal-Organic Frameworks for Record Polymer-Grade Propylene Production under High Humidity Conditions.

Propane/propene (C3 H8 /C3 H6 ) separation is essential in the petrochemical industry but challenging because of their similar physical and chemical properties. Adsorptive separation with C3 H8 -selective porous materials can energy-efficiently produce high-purity C3 H6 , which is highly promising for replacing conventional cryogenic distillation but suffers from unsatisfactory performance. Herein, through the precise incorporation of fluorinated functional groups into the confined pore space, a new fluorinated metal-organic framework (FDMOF-2) featuring the unique and strong C3 H8 -trap is successfully constructed. FDMOF-2 exhibits an unprecedented C3 H8 capture capacity of 140 cm3 cm-3 and excellent C3 H8 /C3 H6 (1:1, v/v) selectivity up to 2.18 (298 K and 1 bar), thus setting new benchmarks for all reported porous materials. Single-crystal X-ray diffraction studies reveal that the tailored pore confinement in FDMOF-2 provides stronger and multiple attractive interactions with C3 H8 , enabling excellent binding affinities. Breakthrough experiments demonstrate that C3 H8 can be directly extracted from various C3 H8 /C3 H6 mixtures with FDMOF-2, affording an outstanding C3 H6 production (501 mmol L-1 ) with over 99.99% purity. Benefiting from the robust framework and hydrophobic ligands, the separation performance of FDMOF-2 can be well maintained even under 70% relative humidity conditions.

Redox-modulated stepwise photochromism in a ruthenium complex with dual dithienylethene-acetylides.

Achieving stepwise photochromism in a combined molecule to access all of the possible ring-open/closed isomers is a challenge due to facile energy transfer from ring-open dithienylethene (DTE) to an adjacent ring-closed moiety that prohibits further photocyclization. The preparation, characterization, and photochromic properties of a bis(σ-acetylide) bonded ruthenium(II) complex 2oo and its oxidized form 2oo(+) with two identical DTE-acetylides (L1o) are described. Stepwise and dual photochromic reactions are successfully achieved in both 2oo and 2oo(+), in which the ring-closing absorption band of 2oo(+) shows an obvious blue-shift relative to 2oo. It is demonstrated that stepwise photochromic reactions 2oo→2co→2cc are more facile than 2oo(+)→2co(+)→2cc(+). The lower electronic density at the reactive carbon atoms upon oxidation of Ru(II) to Ru(III) causes photocyclization to have more difficulty proceeding in oxidized species 2oo(+)/2co(+). Upon dual ring-closure, 2cc/2cc(+) exhibits significant electronic interaction between two identical ring-closed DTE units across trans-Ru(dppe)(2) spacer. The interconversion processes among six states are unambiguously demonstrated by NMR, UV-vis-NIR, and IR spectroscopic, and electrochemical and computational studies.

Gold(I)-coordination triggered multistep and multiple photochromic reactions in multi-dithienylethene (DTE) systems.

The preparation, characterization, and photochromic properties of a mononuclear gold(I) complex (1oo) with two identical DTE-acetylides and a dinuclear gold(I) complex (2ooo) with both DTE-acetylide and DTE-diphosphine are described. Both gold(I) complexes exhibit multistep and multiple photocyclization/cycloreversion reactions. Particularly, four-state and four-color photochromic switch is successfully achieved for the dinuclear gold(I) complex upon irradiation with appropriate wavelengths of light. In contrast, fully ring-closed form is unattained through multiple photocyclization for the two corresponding model organic compounds coupling with the same DTE units as gold(I) complexes but without gold(I)-participation. It is demonstrated that coordination of gold(I) ion to DTE-acetylides exerts indeed a crucial role in achieving stepwise and selective photocyclization and cycloreversion reactions for both gold(I) complexes, in which the coordinated gold(I) atom acts as an effective "barrier" to prohibit intramolecular energy transfer between multi-DTE moieties.