Reaction of the heterometallic cluster Os3Ru(μ-H)2(CO)13 with diphenylphosphine: phosphido-bridged tetrahedral and butterfly clusters

TMNO-activated reaction of the heteronuclear cluster Os₃Ru(μ-H)₂(CO)₁₃ (1) with diphenylphosphine afforded the novel phosphido-bridged clusters Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₁ (2), Os₃Ru(μ-PPh₂)₂(μ-H)₂(CO)₁₀ (3), Os₃Ru(μ-PPh₂)₂(μ-H)₄(CO)₉ (4), and Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₁(PPh₂H) (5). The formation of 2-5 proceeded via P-H bond cleavage in the adduct Os₃Ru(μ-H)₂(CO)₁₂(PPh₂H) (6). Reaction of 2 with PPh₃ afforded the adduct Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₁(PPh₃) (7) and the substituted derivative Os₃Ru(μ-PPh₂)(μ-H)₃(CO)₁₀(PPh₃) (8).     

Versatile Three‐Dimensional Porous Cu@Cu2O Aerogel Networks as Electrocatalysts and Mimicking Peroxidases

A facile strategy is presented to form 3D porous Cu@Cu₂O aerogel networks by self‐assembling Cu@Cu₂O nanoparticles with the diameters of ca. 40 nm for constructing catalytic interfaces. Unexpectedly, the prepared Cu@Cu₂O aerogel networks display excellent electrocatalytic activity to glucose oxidation at a low onset potential of ca. 0.25 V. Moreover, the Cu@Cu₂O aerogels also can act as mimicking‐enzymes including horseradish peroxidase and NADH peroxidase, and show obvious enzymatic catalytic activities to the oxidation of dopamine (DA), o‐phenyldiamine (OPD), 3,3,5,5‐tetramethylbenzidine (TMB), and dihydronicotinamide adenine dinucleotide (NADH) in the presence of H₂O₂. These 3D Cu@Cu₂O aerogel networks are a new class of porous catalytic materials as mimic peroxidases and electrocatalysts and offer a novel platform to construct catalytic interfaces for promising applications in electrochemical sensors and artificial enzymatic catalytic systems.     

β‐AgVO3 Nanorods as Peroxidase Mimetic for Colorimetric Determination of Glucose

β‐AgVO₃ nanorods have been demonstrated to exhibit intrinsic peroxidase‐like activity. The oxidation of glucose can be catalyzed by glucose oxidase (GOx ) to generate H₂O₂ in the presence of O₂ . The β‐AgVO₃ nanorods can catalytically oxidize peroxidase substrates including o‐phenylenediamine (OPD ), 3,3′,5,5′‐tetramethylbenzidine (TMB ), and diammonium 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonate) (ABTS ) by H₂O₂ to produce typical color reactions: OPD from colorless to orange, TMB from colorless to blue, and ABTS from colorless to green. The catalyzed reaction by the β‐AgVO₃ nanorods was found to follow the characteristic Michaelis–Menten kinetics. Compared with horseradish peroxidase and AgVO₃ nanobelts, β‐AgVO₃ nanorods showed a higher affinity for TMB with a lower Michaelis–Menten constant (K _m) value (0.04118 mM ) at the optimal condition. Taking advantage of their high catalytic activity, the as‐synthesized β‐AgVO₃ nanorods were utilized to develop a colorimetric sensor for the determination of glucose. The linear range for glucose was 1.25–60 μM with the lower detection limit of 0.5 μM . The simple and sensitive GOx ‐β–AgVO₃ nanorods–TMB sensing system shows great promise for applications in the pharmaceutical, clinical, and biosensor detection of glucose.     

“Olefin metathesis” reactions of (η5-C5H5)NiRu3(μ-H)(CO)9-(μ4-η2)-(CCHBut) and related complexes

The complex (η⁵-C₅H₅)NiRu₃(μ-H)(CO)₉(μ₄-η²-CCHBu^t) (1a) reacts with olefins to give several organic products, including species derived from the coupling of the vinylidene ligand with an olefin-derived =CRR′ fragment, representing the first example of a (non catalytic) olefin metathesis reaction involving a metal cluster; other complexes structurally or chemically related to the compound 1a have also been treated with olefins and alkynes.     

Nanoreactors derived from silica-protection-assisted metal-organic framework

The construction of highly stable and regular nanoreactors is a major challenge. In this work, we use a facile template protection method to obtain ZIF-67@SiO₂ (JS) and to encapsulate metal oxide nanoparticles (Co₃O₄) into nanoreactors (SiO₂). ZIF-67 crystals provide a cobalt species; SiO₂ was first used as a protective layer of ZIF-67 and then as a nanoreactor for metastable metal oxide nanoparticles. On this basis, Co₃O₄@SiO₂ with dodecahedron morphology were synthesized by calcining JS at different temperatures, followed by a hydrothermal reaction to obtain Co₃(OH)₄Si₂O₅. Subsequently, CoS_x and CoP-SiO₂ were fabricated through sulfuration and phosphorization. The results in this work show that nanoreactors derived from metal-organic frameworks (MOFs) with a rational structure have broad development prospects.     

Glycal-ruthenium carbonyl clusters: Syntheses, characterization, and anticancer activity

Four new chiral ruthenium carbonyl cluster complexes Ru₃(μ-H)₂(CO)₉(L-2H) (1), Ru₃(μ-H)₂(CO)₇(L-2H)(dppm) (2), Ru₃(μ-H)₂(CO)₇(L-2H)(PPh₃)₂ (3), Ru₃(μ-H)₂(CO)₇(L-2H)(dppe) (4) containing a dehydrogenated form (L-2H) of 3,4,6-tri-O-benzyl-d-galactal (L) as a chiral ligand have been prepared and characterized. The anticancer activity of five compounds 1-4 and Ru₃(μ-H)₂(CO)₉(L-2H) 5 (L = tribenzyl glucal) against six types of human cancer cell lines was studied and compared to cisplatin. Compound 1 was chosen to produce more detailed growth curves based on overall highest activity profile. The structure of compound 2 was established by a single-crystal X-ray diffraction analysis. The structure based on triangular metal framework contains a bridging dehydrogenated tribenzyl galactal ligand bonded in a parallel μ₃-η²-bonding mode and a bridging dppm ligand. Variable-temperature NMR studies show that the two hydride ligands in compounds 1 and 2 are dynamically active on the NMR time scale at room temperature.     

Studies on the reactivity of the clusters [Ru3(CO)8(μ-H)2(μ-PR2)2] (R=But,Cy) towards phosphine ligands

The reaction behavior of the 48e-clusters [Ru₃(CO)₈(μ-H)₂(μ-PR₂)₂] (R=Bu^t, 1a; R=Cy, 1b) towards phosphine ligands has been studied. Whereas 1a reacts spontaneously with many phosphines at room temperature, a lack of reactivity for 1b under similar conditions is observed. Thus 1a reacts with dppm (Ph₂PCH₂PPh₂) to the known 46e-cluster [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-PBu^t₂)₂(μ-dppm)] (2a), and the reaction of 1a with dppe (Ph₂PC₂H₄PPh₂) yields analogously [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-PBu^t₂)₂(μ-dppe)] (3). Reactions of 1a with dmpm (Me₂PCH₂PMe₂), dmpe (Me₂PC₂H₄PMe₂) and PBuⁿ₃, respectively, gave in each case a mixture of products which could not be characterized. Contrary to the reaction behavior at room temperature, 1b reacts with phosphines in THF under reflux yielding the novel complexes [Ru₃(CO)₆(μ-H)₂(μ-PCy₂)₂L₂] (L=Cy₂PH, 4a; L=Bu^t₂PH, 4b; L=Ph₂PH, 4c; L=P(OEt)₃, 4d). 4a is also obtained directly by the reaction of [Ru₃(CO)₁₂] with an excess of Cy₂PH. The molecular structure of 4a has been determined by a single-crystal X-ray analysis. Moreover, the thermolysis of 1a in octane affords [Ru₃(CO)₈(μ-H)₂(μ₃-PBu^t)(Bu^t₂PH)] (6) as the main product, and the thermolysis of [Ru₃(CO)₉(Bu^t₂PH)(μ-dppm)] (7) yields 2a to a considerable extent. Treatment of 1a with carbon tetrachloride leads to [Ru₃(CO)₇(μ-H)(μ-PBu^t₂)₂(μ-Cl)] (8) as the main product.     

Activation of C–H and H–H bonds by dinuclear iridium complexes. Oxidative addition to highly active unsaturated 32e− diiridium species

Reactions of [(Cp¹Ir)₂(μ-dmpm)(μ-H)₂][OTf]₂ (1) with NaO^tBu in aromatic solvent at room temperature give [(Cp¹Ir)(H)(μ-dmpm)(μ-H)(Cp¹Ir)(Ar)][OTf] [Ar = Ph (3), p-Tol (4a), m-Tol (4b), 2-furyl (5a), 3-furyl (5b)] via intermolecular aromatic C–H activation. Treatment of [(Cp¹Ir)₂(μ-dppm)(μ-H)₂][OTf]₂ (2) with weak base (Et₂NH) results in intramolecular C–H activation of a phenyl group in the dppm ligand to give [(Cp¹Ir)(H){μ-PPh(C₆H₄)CH₂PPh₂}(μ-H)(Cp¹Ir)][OTf] (6). Reaction of 1 with NaO^tBu in tetrahydrofuran under H₂ (1 atm) results in activation of the H–H bond to give [{(Cp¹Ir)(H)}₂(μ-dmpm)(μ-H)][OTf] (7). Reaction of 1 with NaO^tBu in dichloromethane under carbon monoxide (1 atm) gives a carbonyl-bridged Ir^II–Ir^II complex, [(Cp¹Ir)₂(μ-dmpm)(μ-H)(μ-CO)][OTf] (8-OTf). These results strongly suggest that the active species in C–H and H–H bond activation starting with 1 and 2 would be unsaturated 32e^? diiridium species. The structures of 3, 5a, 6, 7, and 8-BPh₄ have been determined by X-ray diffraction methods.     

Facile cleavage of a phenyl group from SbPh3 by dirhenium carbonyl complexes

The complex Re₂(CO)₈[μ-η²-C(H)C(H)Buⁿ](μ-H) (1) reacts with SbPh₃ at 68 °C to yield the new σ-phenyl dirhenium complex Re₂(CO)₈(SbPh₃)(Ph)(μ-SbPh₂) (4) in 72% yield. Compound 4 contains two rhenium atoms held together by a bridging SbPh₂ ligand. One rhenium atom contains a σ-phenyl group. The other rhenium atom contains a SbPh₃ ligand. Compound 4 was also obtained in 34% yield from the reaction of Re₂(CO)₁₀ with SbPh₃ in the presence of UV–Vis irradiation together with some monorhenium products: HRe(CO)₄SbPh₃ (5), Re(Ph)(CO)₄SbPh₃ (6) and fac-Re(Ph)(CO)₃(SbPh₃)₂ (7) in low yields. Complex 4 is split by reaction with an additional quantity of SbPh₃ to yield the monorhenium SbPh₃ complexes 6, 7 and mer-Re(Ph)(CO)₃(SbPh₃)₂ (8) that contain a σ-phenyl ligand. When 4 was treated with hydrogen, the phenyl ligand was eliminated as benzene and the dirhenium complexes Re₂(CO)₈(μ-SbPh₂)(μ-H) (10), and Re₂(CO)₇(SbPh₃)(μ-SbPh₂)(μ-H) (11), were formed that contain a bridging hydrido ligand. The doubly SbPh₂-bridged dirhenium complex Re₂(CO)₇(SbPh₃)(μ-SbPh₂)₂ (9) that has no metal–metal bond was also formed in these two reactions.     

Synthesis,characterization, and reactivity of a novel ruthenium carbonyl cluster containing tri-O-benzyl-d-glucal as a chiral carbohydrate ligand

A chiral carbohydrate ligand 3,4,6-tri-O-benzyl-d-glucal (L) reacts with the cluster triruthenium dodecacarbonyl Ru₃(CO)₁₂ giving a novel chiral cluster Ru₃(μ-H)₂(CO)₉(L-2H) (I) that shows fluxional behavior at room temperature. The reaction of Ru₃(μ-H)₂(CO)₉(L-2H) (I) with triphenylphosphine and diphenylphosphinoethane (dppe) gives two new clusters Ru₃(μ-H)₂(CO)₇(L-2H)(PPh₃)₂ (II) and Ru₃(μ-H)₂(CO)₇(L-2H)(dppe) (III). The new compounds I, II and III have been characterized by a combination of elemental analysis, mass spectrometry, infrared and variable temperature NMR spectroscopy.     

Loading of ZIF-67 on silk with sustained release of iodine as biocompatible antibacterial fibers

Antibacterial fibers have great potential in numerous applications, including bandages, surgical robes, and surgical sutures, and play a significant role in our everyday lives. Here, zeolitic imidazolate framework-67 was synthesized using a green method on silk fibers through a layer-by-layer process under ultrasonic irradiation (ZIF-67@silk [U]) and without ultrasonic irradiation (ZIF-67@silk [B]). Then, iodine was loaded on ZIF-67@silk samples and were assessed as antibacterial fibers with iodine release. Four samples of ZIF-67@silk and I₂@ZIF-67@silk were characterized by FT-IR, PXRD, FE-SEM, TGA, BET, and UV–Vis spectroscopy. Finally, antibacterial activity of ZIF-67@silk (B and U) and I₂@ZIF-67@silk (B and U) on Staphylococcus aureus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria was investigated. In addition to ZIF-67@silk samples, iodine-loaded samples showed excellent antimicrobial facility.     

Reactivity of the heteronuclear cluster Cp*IrOs3(μ-H)2(CO)10 with some group 16 substrates

The mixed metal cluster Cp*IrOs₃(μ-H)₂(CO)₁₀ (1) reacted readily with a number of group 16 substrates under chemical activation with TMNO. It reacted with C₆H₅SH to afford the novel cluster Cp*IrOs₃(μ-H)₃(CO)₉(μ-SPh) (2). It also reacted readily with Ph₃PSe to afford five new clusters, viz., Cp*IrOs₃(μ-H)₂(CO)₉(μ₃-Se) (3) Os₃(μ-H)₂(CO)₇(μ₃-Se)(PPh₃)₂ (4), Cp*IrOs₃(μ-H)₂(CO)₉(PPh₃) (5), Cp*IrOs₃(μ-H)₂(μ₃-Se)(CO)₈(PPh₃) (6) and Cp*IrOs₃(μ-H)₂(μ₃-Se)₂(CO)₇(PPh₃) (7). The reaction pathway for this reaction has been studied carefully and suggests that Ph₃PSe functioned primarily as a selenium atom transfer agent to give initially the even more reactive 3. The reaction of 1 with di-p-tolyl ditelluride yielded three new clusters, 8-10, which were non-interconverting stereoisomers with the formulation Cp*IrOs₃(μ-H)₂(μ-Te-p-C₆H₄CH₃)₂(CO)₈.     

Synthesis and X-ray crystal structure of the electron-deficient metal carbonyl cluster [Os3(CO)5(μ3-H)(μ-H)(μ-PtBu2)2(μ-Ph2PCH2PPh2)]

The reaction of [Os₃(CO)₁₀(μ-dppm)] (1) with ^tBu₂PH in refluxing diglyme results in the electron-deficient metal cluster complex [Os₃(CO)₅(μ₃-H)(μ-P^tBu₂)₂(μ-dppm)] (2) (dppm = Ph₂PCH₂PPh₂) in good yields. The molecular structure of 2 has been established by a single crystal X-ray structure analysis. In contrast to the known homologue [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-P^tBu₂)₂(μ-dppm)] (3), no bridging carbonyl ligand was found in 2. The electronically unsaturated cluster 2 does not react with carbon monoxide under elevated pressure, therefore 2 seems to be coordinatively saturated by reason of the high steric demands of the phosphido ligands.     

Vitamin B3 as a high acid-alkali tolerant peroxidase mimic for colorimetric detection of hydrogen peroxide and glutathione

Small-molecule enzyme mimics as biocatalysts have been extensively applied in diverse colorimetric sensors fabrication. However, excavating potential organic enzyme mimics with high catalytic activity still remains challenging. In this study, the peroxidase mimicking activity of nicotinic acid (VB3) was demonstrated for the first time through chromogenic substrate 3, 3′, 5, 5′-tetramethylbenzidine (TMB) at the existence of hydrogen peroxide (H₂O₂). The catalytic activity of VB3 kept more than 80% of its optimum activity in a broad pH range of 3.0–9.0. In addition, the kinetic parameter (Michaelis constant, K_m = 0.037 mM) of VB3 catalysis to H₂O₂ is smaller than natural horseradish peroxidase (HRP) and previously reported peroxidase mimics. The catalytic mechanism of VB3 is mainly attributed to the active species of hydroxyl radical (OH) and partially attributed to the superoxide free radicals (O₂^?). A convenient and sensitive colorimetric method based on VB3-H₂O₂-TMB chromogenic system for H₂O₂ and glutathione detection was fabricated with the linear ranges of 5.0–100.0 μM and 5.0–50.0 μM, respectively. In short, this work will not only bring new enlightenment on the physiological functions and practical applications in the analytical field of VB3, but also provide a new type of structural reference for small-molecule enzyme mimics.     

Halogen-substituent effect on the spectroscopic properties of 2-phenyl-6-dimethylaminobenzothiazoles

6-Dimethylamino-2-phenylbenzothiazole (1-H) is a push-pull benzothiazole fluorophore mimicking the firefly oxyluciferin structure. We newly prepared 7-chloro and 7-bromo derivatives of 1-H and its 4-acetyl derivative (2-H), and their spectroscopic and photophysical properties were investigated. The halogenated derivatives showed the blue-shifted electronic absorption maxima and fluorescence emission maxima compared to 1-H and 2-H, resulted from the deformations of the NMe₂ groups and the electron withdrawing properties of the halogen groups. In addition, the halogen substitutions accelerate intersystem crossing by heavy atom effect, resulting in a decrease in fluorescence quantum yields. Interestingly, however, the halogenated derivatives of 2-H still showed moderate fluorescence quantum yields. The halogenation effect is one of the guides to design push-pull benzothiazole fluorophores for tuning fluorescence properties.     

Reactions of the triosmium cluster Os3(μ-H)(μ-OH)(CO)10 with naphthols

Reaction of the cluster Os₃(μ-H)(μ-OH)(CO)₁₀ (1) with 1-naphthol afforded the isomeric clusters 2a and 3a with the formulae Os₃(μ-H)₂(μ₃-1-OC₁₀H₆)(CO)₉. A similar reaction with 2-naphthol, however, gave Os₃(μ-H)(μ-2-OC₁₀H₇)(CO)₁₀, 4b, and the analogue of 2a. These clusters have been structurally characterised to confirm the mode of anchoring of the naphthols.     

Reaction of the heteronuclear cluster RuOs3(μ-H)2(CO)13 with azulenes

Reaction of the heteronuclear cluster RuOs₃(μ-H)₂(CO)₁₃ (1) with azulene under thermal activation afforded the novel clusters RuOs₃(μ-H)(CO)₉(μ₃,η⁵:η²:η²-C₁₀H₉) (3) and Ru₂Os₃(μ-H)₂(CO)₁₃(μ-CO)(μ₃,η⁵:σ²-C₁₀H₈) (5a), with 4,6,8-trimethylazulene to give RuOs₃(μ-H)(CO)₈(μ-CO)(μ,η⁵:η⁴-C₁₀H₆Me₃) (4) and Ru₂Os₃(μ-H)₂(CO)₁₃(μ-CO)(μ₃,η⁵:σ²-C₁₀H₅Me₃) (5b), and with guaiazulene to give Ru₂Os₃(CO)₁₁(μ₃,η⁵:η³:η³-C₁₀H₅Me₂ⁱPr) (6), respectively. In 3–5, cluster-to-ligand hydrogen transfer appears to have taken place, with the organic moiety capping a trimetallic face in 3, bridging a metal–metal bond in 4 and via a μ₃,η⁵:σ² bonding mode in 5a and 5b. Cluster 6 contains a trigonal bipyramidal metal framework with the guaiazulene ligand over a triangular metal face. All five clusters have been completely characterised, including by single-crystal X-ray diffraction analysis.     

Addition of primary phosphines to the unsaturated triosmium cluster [(μ-H)Os3(CO)8{Ph2PCH2P(Ph)C6H4}]: Synthesis of triosmium clusters bearing dppm, phosphide and phosphinidene ligands via P-H bond activation

Treatment of the electronically unsaturated cluster [(μ-H)Os₃(CO)₈{Ph₂PCH₂P(Ph)C₆H₄}] (1) with primary phosphines PPhH₂ and PCyH₂ gives the phosphido bridged compounds [(μ-H)Os₃(CO)₈(μ-PPhH)(μ-dppm)] (2) and [(μ-H)Os₃(CO)₈(μ-PCyH)(μ-dppm)] (3), respectively, by P-H bond activation of the phosphines and demetallation of the phenyl ring of the diphosphine ligand. Thermolysis of 2 and 3 in refluxing octane at 128 °C results in the formation of the phosphinidene compounds [(μ-H)₂Os₃(CO)₇(μ₃-PPh)(μ-dppm)] (4) and [(μ-H)₂Os₃(CO)₇(μ₃-PCy)(μ-dppm)] (5), respectively, by further P-H bond cleavage of the phosphido groups. All the compounds have been characterized by infrared, ¹H NMR, ³¹P{¹H} NMR and mass spectroscopic data together with single-crystal X-ray diffraction studies for 4. Compound 4 consists of a triangular cluster of osmium atoms with a symmetrically capped phosphinidene ligand and a bridging dppm ligand.     

Dppm-substituted ruthenium clusters with capping sulfido and selenido ligands derived from thiourea, tetramethylthiourea and elemental selenium

Treatment of [Ru₃(CO)₁₀(μ-dppm)] (4) [dppm = bis(diphenylphosphido)methane] with tetramethylthiourea at 66 °C gave the previously reported dihydrido triruthenium cluster [Ru₃(μ-H)₂(μ₃-S)(CO)₇(μ-dppm)] (5) and the new compounds [Ru₃(μ₃-S)₂(CO)₇(μ-dppm)] (6), [Ru₃(μ₃-S)(CO)₇(μ₃-CO)(μ-dppm)] (7) and [Ru₃(μ₃-S){η¹-C(NMe₂)₂}(CO)₆(μ₃-CO)(μ-dppm)] (8) in 6%, 10%, 32% and 9% yields, respectively. Treatment of 4 with thiourea at the same temperature gave 5 and 7 in 30% and 10% yields, respectively. Compound 7 reacts further with tetramethylthiourea at 66 °C to yield 6 (30%) and a new compound [Ru₃(μ₃-S)₂{η¹-C(NMe₂)₂}(CO)₆(μ-dppm)] (9) (8%). Thermolysis of 8 in refluxing THF yields 7 in 55% yield. The reaction of 4 with selenium at 66 °C yields the new compounds [Ru₃(μ₃-Se)(CO)₇(μ₃-CO)(μ-dppm)] (10) and [Ru₃(μ₃-Se)(μ₃-η³-PhPCH₂PPh(C₆H₄)}(CO)₆(μ-CO)] (11) and the known compounds [Ru₃(μ-H)₂(μ₃-Se)(CO)₇(μ-dppm)] (12) and [Ru₄(μ₃-Se)₄(CO)₁₀(μ-dppm)] (13) in 29%, 5%, 2% and 5% yields, respectively. Treatment of 10 with tetramethylthiourea at 66 °C gives the mixed sulfur-selenium compounds [Ru₃(μ₃-S)(μ₃-Se)(CO)₇(μ-dppm)] (14) and [Ru₃(μ₃-S)(μ₃-Se){η¹-C(NMe₂)₂}(CO)₆(μ-dppm)] (15) in 38% and 10% yields, respectively. The single-crystal XRD structures of 6, 7, 8, 10, 14 and 15 are reported.     

Synthesis and characterization of triosmium and triruthenium pyrene clusters

The reaction between 1-pyrenecarboxaldehyde (C₁₆H₉CHO) and the labile triosmium cluster [Os₃(CO)₁₀(CH₃CN)₂] gives rise to the formation of two new compounds by competitive oxidative addition between the aldehydic group and an arene C-H bond, to afford the acyl complex [Os₃(CO)₁₀(μ-H)(μ-COC₁₆H₉)] (1) and the compound [Os₃(CO)₁₀(μ-H) (C₁₆H₈CHO)] (2), respectively. Thermolysis of [Os₃(CO)₁₀(μ-H)(μ-C₁₆H₉CO)] (1) in n-octane affords two new complexes in good yields, [Os₃(CO)₉(μ-H)₂(μ-COC₁₆H₈)] (3) and the pyryne complex [Os₃(CO)₉(μ-H)₂(μ₃-η¹:η¹:η²-C₁₆H₈)] (4).In contrast, when 1-pyrenecarboxaldehyde reacts with [Ru₃(CO)₁₂] only one product is obtained, [Ru₃(CO)₉(μ-H)₂(μ₃-η¹:η¹:η²-C₁₆H₈)] (5), a nonacarbonyl cluster bearing a pyrene ligand. All compounds were characterized by analytical and spectroscopic data, and crystal structures for 1, 2, 4 and 5 were obtained.