Activation of metal hydride complexes by tri-tert-butylphosphine-platinum and -palladium groups

The compounds HM(CO)4SnPh3, M = Os (10), Ru (11) are activated in the presence of Pt(PBut3)2 and Pd(PBu(t)3)2 toward the insertion of PhC2H into the M-H bond. The compounds PtOs(CO)4(SnPh3)(PBu(t)3)[mu-HCC(H)Ph], 12, and PtOs(CO)4(SnPh3)(PBu(t)3)[mu-H2CCPh], 13, were obtained from the reaction of 10 with PhC2H in the presence of Pt(PBu(t)3)2. Compounds 12 and 13 are isomers containing alkenyl ligands formed by the insertion of the PhC2H molecule into the Os-H bond at both the substituted and unsubstituted carbon atoms of the alkyne. Both compounds contain a Pt(PBu(t)3) group that is bonded to the osmium atom and a bridging alkenyl ligand that is pi-bonded to the osmium atom. The reaction of 11 with PhC2H in the presence of Pt(PBu(t)3)2 yielded the products PtRu(CO)4(SnPh3)(PBu(t)3)[mu-HC2(H)Ph], 14, and PtRu(CO)4(SnPh3)(PBut3)[mu-H2C2Ph], 15, which are also isomers similar to 12 and 13. The reaction of 11 with PhC2H in the presence of Pd(PBu(t)3)2 yielded the product PdRu(CO)4(SnPh3)(PBu(t)3)[mu-H2C2Ph], 16. Compound 16 contains a Pd(PBu(t)3) group bonded to the ruthenium atom and a bridging H2C2Ph ligand that is pi-bonded to the palladium atom. Compound 10 reacted with Pt(PBu(t)3)2 in the absence of PhC2H to yield the compound PtOs(CO)4(SnPh3)(PBu(t)3)(mu-H), 17. Compound 17 is a Pt(PBu(t)3) adduct of 10. It contains a Pt-Os bond with a bridging hydrido ligand. Compound 17 reacted with PhC2H to yield 12. Compound 12 reacted with PhC2H to yield the compound PtOs(CO)3(SnPh3)(PBu(t)3)[mu-HCC(Ph)C(H)C(H)Ph], 18. Compound 18 contains a bridging 2,4-diphenylbutadienyl ligand, HCC(Ph)C(H)C(H)Ph, that is pi-bonded to the osmium atom and sigma-bonded to the platinum atom. Fenkse-Hall molecular orbitals of 17 were calculated. The LUMO of 17 exhibits an empty orbital on the platinum atom that appears to be the most likely site for PhC2H addition prior to its insertion into the Os-H bond.     

Hydrogen–Deuterium Exchange Reactions of Aromatic Compounds and Heterocycles by NaBD4‐Activated Rhodium,Platinum and Palladium Catalysts

Conventional thermal and microwave conditions were compared for hydrogen–deuterium (H/D) exchange reactions of aminobenzoic acids catalysed by NaBD₄‐activated Pd/C or RhCl₃ with D₂O as the deuterium source. We also investigated different NaBD₄‐activated metal catalysts (including Pd/C, RhCl₃ and Pt/C) under microwave conditions for an efficient H/D exchange of aromatic and heterocyclic compounds. Even higher deuterium incorporations were obtained for Pd/C and Pt/C catalyst mixtures due to the previously observed synergistic effect. Finally, we have applied these optimised conditions for one‐step syntheses of the MS standards of several pharmaceutically active compounds.     

乙烷在Pt/γ-Al2O3（001）模型催化剂上吸附行为的理论研究

本文采用密度泛函理论方法和周期性边界条件,考察了Pt原子与γ-Al2O3(001)表面上六种不同位点的相互作用,获得了最稳定吸附位的Pt/γ-Al2O3模型催化剂,建立了Pt原子负载在γ-Al2O3(001)表面的模型催化剂。同时,考查了乙烷分子在Pt/γ-Al2O3模型催化剂上的吸附行为。结果表明,在Pt/γ-Al2O3模型催化剂上,Pt原子转移了部分电子到载体γ-Al2O3。乙烷以分子态形式吸附在Pt/γ-Al2O3模型催化剂上,靠近Pt原子的C-H键受到一定程度地活化。     

A small paramagnetic platinum cluster in an NaY zeolite: characterization and hydrogen adsorption and desorption

A well-defined cluster containing 12 equivalent platinum atoms was prepared by ion exchange of an NaY zeolite, followed by hydrogen reduction. It was characterized by electron paramagnetic resonance (EPR) spectroscopy, hyperfine sublevel correlation (HYSCORE), and theoretical calculations. Combing the results of the experiments with density functional calculations, the likely structure of this cluster is icosahedral Pt13Hm, possibly with a low positive charge. The adsorbed H/D on the Pt cluster surface can be exchanged reversibly at room temperature. From H/D desorption experiments, an H2 binding energy of 1.36 eV is derived, in reasonable agreement with the calculated value but clearly larger than that for a (111) Pt single-crystal surface, revealing a finite size effect. While the hydrogen-covered cluster should clearly be regarded as a molecule, it is conceivable that the cluster adopts metallic character upon hydrogen desorption. It is likely that up to m=30 H atoms bind to this cluster with 12 surface atoms, which has important implications for the determination of the dispersion of small Pt catalyst particles by hydrogen chemisorption. Calculations as well as experiments give evidence of an interesting magnetic behavior with high-spin states playing a prominent role. There are strong indications that a reservoir of EPR silent but structurally similar clusters exists which can partly be converted to EPR visible species by H/D exchange or by gas adsorption.     

氨基醇砌块用于螺/环丙环类手性化合物的合成

手性氨基醇砌块3与5-(l-孟氧基)-3-溴-2(5H)-呋喃酮手性合成子4通过串联的不对称双Michael加成/分子内亲核取代反应,得到了具有四个新的手性中心的氨基醇手性砌块/螺环/环丙烷类化合物7(44%～57%,de≥98%)。通过元素分析,[α]^20~D,UV,IR,^1HNMR,^13CNMR,MS确认了它们的化学结构。本工作可以为含有某些活性官能团的多手性中心的复杂结构化合物提供新的合成策略。     

Competition at chiral metal surfaces: fundamental aspects of the inversion of enantioselectivity in hydrogenations on platinum

O-Phenylcinchonidine (PhOCD) is known to efficiently induce inversion of enantioselectivity with respect to cinchonidine (CD) in the enantioselective hydrogenation of various activated ketones on Pt/Al(2)O(3). To understand the origin of the switch of enantioselective properties of the catalyst, the adsorption of PhOCD has been studied by in situ ATR-IR spectroscopy, in the presence of organic solvent and dissolved hydrogen, i.e., under conditions used for catalytic hydrogenation. The adsorption structures and energies of the anchoring group of CD and PhOCD were calculated on a Pt 38 cluster, using relativistically corrected density functional theory (DFT). Both approaches indicate that both modifiers are adsorbed via the quinoline ring and that the spatial arrangement of the quinuclidine skeleton is critical for the chiral recognition. New molecular level information on the conformation of CD relative to PhOCD adsorbed on a surface is extracted from the ATR spectra and supported by DFT calculations. The result is a clearer picture of the role played by the phenyl group in defining the chiral space created by the modifiers on Pt. Moreover, when CD was added to a pre-equilibrated adsorbed layer of PhOCD, a chiral adsorbed layer was formed with CD as the dominant modifier, indicating that CD adsorbs more strongly than PhOCD. Conversely, when PhOCD was added to preadsorbed CD, no significant substitution occurred. The process leading to nonlinear effects in heterogeneous asymmetric catalysis has been characterized by in situ spectroscopy, and new insight into a heterogeneous catalytic R-S switch system is provided.     

Evidence for site‐specific intra‐ionic hydrogen/deuterium exchange in the low‐energy collision‐induced dissociation product ion spectra of protonated small molecules generated by electrospray ionisation

The experimental investigation of site‐specific intra‐ionic hydrogen/deuterium (H/D) exchange in the low‐energy collision‐induced dissociation (CID) product ion spectra of protonated small molecules generated by electrospray ionisation (ESI) is presented. The observation of intra‐ionic H/D exchange in such ions under low‐energy CID conditions has hitherto been rarely reported. The data suggest that the intra‐ionic H/D exchange takes place in a site‐specific manner between the ionising deuteron, localised at either a tertiary amine or a tertiary amine‐N‐oxide, and a γ‐hydrogen relative to the nitrogen atom. Nuclear magnetic resonance (NMR) spectroscopy measurements showed that no H/D exchange takes place in solution, indicating that the reaction occurs in the gas phase. The compounds analysed in this study suggested that electron‐withdrawing groups bonded to the carbon atom bearing the γ‐hydrogen can preclude exchange. The effect of the electron‐withdrawing group appears dependent upon its electronegativity, with lower χ value groups still allowing exchange to take place. However, the limited dataset available in this study prevented robust conclusions being drawn regarding the effect of the electron‐withdrawing group. The observation of site‐specific intra‐ionic H/D exchange has application in the area of structural elucidation, where it could be used to introduce an isotopic label into the carbon skeleton of a molecule containing specific structural features. This could increase the throughput, and minimise the cost, of such studies due to the obviation of the need to produce a deuterium‐labelled analogue by synthetic means. Copyright © 2010 John Wiley & Sons, Ltd.     

Ab initio multireference configuration-interaction study of hydrogen molecule activation by Cs-promoted Pt clusters

The adsorption of the H2 molecule on CsnPt(5-n) bcc (111) clusters for Cs/Pt rates of 20%, 40%, and 80% is studied using ab initio multiconfigurational self-consistent field plus multireference configuration-interaction variational and perturbative calculations. The H2 interaction with the clusters is studied in ground and excited states with geometry optimization, where the hydrogen adsorption takes place by a Pt atom. These calculations are compared with those of H2 adsorption on Pt4. The most stable configurations of Cs/Pt4 and Cs2Pt3 clusters (Cs/Pt rates of 20% and 40%) are a doublet and a closed-shell singlet, respectively. Both clusters capture and activate the hydrogen molecule and their behaviors resemble Pt4. The H2 capture distances are, respectively, similar and smaller than Pt4 capture distances, while the H-H bond dissociation distances are similar and bigger than those of Pt4; however, none of them presents activation barriers. The most stable Cs4Pt cluster (Cs/Pt rate of 80%) is also a closed-shell singlet; it also captures and activates the hydrogen molecule and shows a different behavior as compared with Cs/Pt4, Cs2Pt3, and Pt4 clusters. The capture distance is quite smaller and is obtained after surmounting an activation barrier. For all clusters studied here, no hydrogen absorption was observed, only the adsorption of H2.     

Adsorption and co-adsorption of ethylene and carbon monoxide on silica-supported monodisperse Pt nanoparticles: volumetric adsorption and infrared spectroscopy studies

The adsorption of carbon monoxide and ethylene, and their sequential adsorption, was studied over a series of Pt/SBA-15 catalysts with monodisperse particle sizes ranging from 1.7 to 7.1 nm by diffuse-reflectance infrared spectroscopy and chemisorption. Gas adsorption was dependent on the Pt particle size, temperature, and sequence of gas exposure. Adsorption of CO at room temperature on Pt/SBA-15 gives rise to a spectroscopic feature assigned to the C-O stretch: nu(CO) = 2075 cm-1 (1.9 nm); 2079 cm-1 (2.9 nm); 2082 cm-1 (3.6 nm); and 2090 cm-1 (7.1 nm). The intensity of the signal decreased in a sigmoidal fashion with increasing temperature, thereby providing semiquantitative surface coverage information. Adsorption of ethylene on Pt/SBA-15 gave rise to spectroscopic features at approximately 1340, approximately 1420, and approximately 1500 cm-1 assigned to ethylidyne, di-sigma-bonded ethylene, and pi-bonded ethylene, respectively. The ratio of these surface species is highly dependent on the Pt particle size. At room temperature, Pt particles stabilize ethylidyne as well as di-sigma- and pi-bonded ethylene; however, ethylidyne predominated on the surfaces of larger particles. Ethylidyne was the only identifiable species at 403 K, with its formation being more facile on larger particles. Co-adsorption experiments reveal that the composition of the surface layer is dependent on the order of exposure to gases. Exposure of a C2H4-covered Pt surface to CO resulted in an approximately 50% decrease in chemisorbed CO compared to a fresh Pt surface. The nu(CO) appeared at 2050 cm-1 on Pt/SBA-15 pretreated with C2H4 at room temperature. The di-sigma-bonded and pi-bonded species are the most susceptible to displacement from the surface by CO. The formation of ethylidyne appeared to be less sensitive to the presence of adsorbed carbon monoxide, especially on larger particles. Upon exposure of C2H4 to a CO-covered Pt surface, little irreversible uptake occurred due to nearly 100% site blocking. These results demonstrate that carbon monoxide competes directly with ethylene for surface sites, which will have direct implications on the poisoning of the heterogeneously catalyzed conversion of hydrocarbons.     

Study of Hydrogen Adsorption on Pt/WO3-ZrO2 through Pt Sites

The rate determining step and the energy barrier involved in hydrogen adsorption on Pt/WO_3- ZrO_2 were studied based on the assumption that the hydrogen adsorption occurs only through Pt sites. The rate of hydrogen adsorption on Pt/WO_3-ZrO_2 was measured in the adsorption temperature range of 323-573 K and an initial hydrogen pressure of 50 Torr.The rates of hydrogen uptake were very high for the initial few minutes and the adsorption continued for more than 5 h below 523 K.The hydrogen uptake far exceeded the H/Pt ratio of unity for all adsorption temperatures,indicating that the adsorption of hydrogen involved the dissociative adsorption of hydrogen on Pt sites to form hydrogen atoms,the spillover of hydrogen atoms onto the surface of the WO_3-ZrO2 catalyst,the diffusion of spiltover hydrogen atom over the surface of the WO_3-ZrO_2 catalyst,and the formation of protonic acid site originated from hydrogen atom by releasing an electron in which the electron may react with a second hydrogen atom to form a hydride near the Lewis acid site.The rate determining step was the spillover with the activation energy of 12.3 kJ/mol.The rate of hydrogen adsorption cannot be expressed by the rate equation based on the assumption that the rate determining step is the surface diffusion.The activity of Pt/WO_3-ZrO_2 was examined on n-heptane isomerization in which the increase of hydrogen partial pressure provided positive-effect on the conversion of n-heptane and negative-effect on the selectivity towards iso-heptane.     

Pt(DVDS)-Phan催化的末端炔烃的硅氢加成反应

以Pt(DVDS)-Phan体系作为末端炔烃与三乙基硅烷或三苯基硅烷进行硅氢加成的催化剂, 除三甲基硅乙炔与三乙己硅烷反应外, 其余反应的收率均高于90%, 并且高选择性地或唯一地得到马氏加成产物或者反马氏反式加成产物, 立体选择性或区域选择性超过95%.     

An in situ attenuated total reflection infrared study of a chiral catalytic solid-liquid interface: cinchonidine adsorption on pt.

An in situ attenuated total reflection study of the chiral solid-liquid interface created by cinchonidine adsorption on a Pt/Al(2)O(3) model catalyst is presented. Experiments were performed in the presence of dissolved hydrogen, that is under conditions used for the heterogeneous enantioselective hydrogenation of alpha-functionalized ketones. Cinchonidine adsorbs via the quinoline moiety. The adsorption mode is coverage dependent and several species coexist on the surface. At low concentration (10(-6)M) a predominantly flat adsorption mode prevails. At increasing coverage two different tilted species, alpha-H abstracted and N lone pair bonded cinchonidine, are observed. The latter is only weakly bound and in a fast dynamic equilibrium with dissolved cinchonidine. At high concentration (10(-4)-10(-3) M) all three species coexist on the Pt surface. A slow transition from an adsorbate layer with a high fraction of alpha-H abstracted cinchonidine to one with a high fraction of N lone pair bonded cinchonidine is observed with the cinchonidine concentration being the driving force for the process. The reverse transition in the absence of dissolved cinchonidine is fast. Cinchonidine competes with solvent decomposition products for adsorption sites on the Pt, which may contribute to the observed solvent dependence of the heterogeneous enantioselective hydrogenation of ketones by cinchonidine-modified Pt.     

1-丁基-3-甲基咪唑硫酸氢盐离子液体与含氮化合物相互作用的理论研究

采用密度泛函理论方法研究了1-丁基-3-甲基咪唑硫酸氢盐离子液体[Bmim]HSO_4与氮化物喹啉和吲哚分子的相互作用,并进行了NBO和AIM分析。[Bmim]HSO_4离子对最稳定结构表明,[HSO_4]~-阴离子中的氧原子与咪唑环中正电性较大的C14-H20之间有较强的氢键作用。在分子水平上,NBO和AIM分析证实了喹啉和吲哚分子与[Bmim]HSO_4的阴离子之间有较强的相互作用,其中,喹啉分子中的氮原子与阴离子[HSO_4]~-中氢原子之间的作用以及吲哚分子中N-H的氢原子与[HSO_4]~-中氧原子之间的作用是该离子液体能够有效脱除氮化物的主要动力。     

Ion–Molecule Reactions of “Rollover” Cyclometalated [Pt(bipy−H)]+ (bipy=2,2′‐bipyridine) with Dimethyl Ether in Comparison with Dimethyl Sulfide: An Experimental/Computational Study

The ion–molecule reactions of dimethyl ether with cyclometalated [Pt(bipy?H)]⁺ were investigated in gas‐phase experiments, complemented by DFT methods, and compared with the previously reported ion–molecule reactions with its sulfur analogue. The initial step corresponds in both cases to a platinum‐mediated transfer of a hydrogen atom from the ether to the (bipy?H) ligand, and three‐membered oxygen‐ and sulfur‐containing metallacycles serve as key intermediates. Oxidative C? C bond coupling (“dehydrosulfurization”), which dominates the gas‐phase ion chemistry of the [Pt(bipy?H)]⁺ ion with dimethyl sulfide, is practically absent for dimethyl ether. The competition in the formation of C₂H₄ and CH₂X (X=O, S) in the reactions of [Pt(bipy?H)]⁺ with (CH₃)₂X (X=O, S) as well as the extensive H/D exchange observed in the [Pt(bipy?H)]⁺/(CH₃)₂O system are explained in terms of the corresponding potential‐energy surfaces.     

First-principles study on the reconstruction induced by the adsorption of C60 on Pt(111)

The adsorption of C60 on a Pt(111) surface and the origins of the √13 × √13R13.9° or 2√3 × 2√3R30° reconstruction of the C60/Pt(111) system have been investigated by means of first-principles calculations. In agreement with the experimental observations, our calculations reveal that the C60 molecule binds covalently on the Pt(111) surface. The C60 molecule adsorbs on the Pt(111) surface with the center of a hexagonal ring located on top of a surface Pt atom. The surface Pt atom can be removed easily, forming a Pt vacancy upon the adsorption of C60 molecule. Our calculation results show that the strong covalent bonds between C60 and the Pt(111) surface and the formation of adatom-vacancy pairs in the C60/Pt(111) system may be the main driving forces promoting the substrate reconstructing pattern observed in experiments.     

二(β-羟亚胺)二氯化钛配合物的合成及催化乙烯聚合

报道了3个β-羟亚胺配体(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂CH(Ph)OH(1a), (2,6-^emPr₂C₆H₃)N＝C·(Ph)CH₂C(Ph)₂OH(1b)和(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂C(C₁₂H₈)OH(1c)及其二(β-羟亚胺)二氯化钛配合物[(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂CH(Ph)O]₂TiCl₂(2a), [(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂C(Ph)₂O]₂·TiCl₂(2b)和[(2,6-^emPr₂C₆H₃)N＝C(Ph)CH₂C(C₁₂H₈)O]₂TiCl₂(2c)的合成, 并对其结构进行了表征. 在助催化剂甲基铝氧烷(MAO)作用下, 以化合物2b为主催化剂, 研究了Al/Ti摩尔比、 反应时间、 温度和聚合压力等对乙烯聚合的影响, 发现该催化体系在较宽的反应条件下均可得到很高分子量的聚乙烯, 熔点均在140℃左右. 以化合物2a~2c为主催化剂对乙烯进行催化聚合, 发现在β碳位上取代基的立体位阻对催化剂活性有很大影响. 当化合物2b上引入2个苯基取代基时, 催化剂显示出最佳催化活性.     

Platinum promoted insertion of an alkyne into a metal-hydrogen bond

HOs(CO)4SnPh3, 1 reacts with PhC2H in the presence to Pt(PBut3)2 to yield the alkyne insertion product PtOs(CO)4(SnPh3)(PBut3)[mu-HC2(H)Ph], 2 containing a Pt(PBut3)(CO) group coordinated to the osmium atom and the alkenyl ligand. In the absence of PhC2H, 1 reacts with Pt(PBut3)2 to form a Pt(PBut3) adduct, PtOs(CO)4(SnPh3)(PBut3)(mu-H), 3 at the Os-H bond. This adduct is readily transformed to 2 upon reaction with PhC2H. In the absence of the Pt(PBut3) promoter, PhC2H does not react with 1.     

Platinum-catalyzed asymmetric alkylation of secondary phosphines: enantioselective synthesis of p-stereogenic phosphines

The chiral Pt catalyst precursor Pt((R,R)-Me-Duphos)(Ph)(Cl) mediated alkylation of racemic secondary phosphines PHR(R') with benzyl halides in the presence of base to give enantioenriched tertiary phosphines PR(R')(CH2Ar). Similar reactions of bis(secondary) phosphines yielded chiral diphosphines in up to 93% ee and with good rac/meso diastereoselection.     

PtMo催化剂抗SO2中毒机理的DFT研究

空气中的杂质气体如SO2能使燃料电池阴极催化剂Pt中毒,降低催化剂的活性和稳定性,而Mo原子的掺杂则能有效提高Pt催化剂的活性和抗SO2中毒性.据此我们采用密度泛函理论分析Mo掺杂提高Pt催化剂抗SO2毒性的原因,Pt与掺杂Mo之间的原子比为8：1.首先,分别计算SO2及解离中间物种S和SO3在Pt（111）和PtMo（111）表面的吸附构型,获得各物种的几何、电子构型.然后,通过比较各吸附物种在Pt（111）和PtMo（111）面的吸附能、键长、键角变化,分析吸附前后Pt（111）和PtMo（111）面分态密度、d带中心以及差分电子密度的变化.结果发现：Mo的掺杂明显减弱了Pt-S间的相互作用,降低SO2、S、SO3在PtMo（111）表面的吸附能;Mo减弱了SO2吸附对PtMo（111）体系电子构型的影响,使催化剂尽量保持原有的电子构型及活性.     

Reversible capture of small molecules on bimetallaborane clusters: synthesis, structural characterization, and photophysical aspects

Metallaborane compounds containing two adjacent metal atoms, [(PMe(2)Ph)(4)MM'B(10)H(10)] (where MM' = Pt(2), 1; PtPd, 7; Pd(2), 8), have been synthesized, and their propensity to sequester O(2), CO, and SO(2) and to then release them under pulsed and continuous irradiation are described. Only [(PMe(2)Ph)(4)Pt(2)B(10)H(10)], 1, undergoes reversible binding of O(2) to form [(PMe(2)Ph)(4)(O(2))Pt(2)B(10)H(10)] 3, but solutions of 1, 7, and 8 all quantitatively take up CO across their metal-metal vectors to form [(PMe(2)Ph)(4)(CO)Pt(2)B(10)H(10)] 4, [(PMe(2)Ph)(4)(CO)PtPdB(10)H(10)] 10, and [(PMe(2)Ph)(4)(CO)Pd(2)B(10)H(10)] 11, respectively. Crystallographically determined interatomic M-M distances and infrared CO stretching frequencies show that the CO molecule is bound progressively more weakly in the sequence {PtPt} > {PtPd} > {PdPd}. Similarly, SO(2) forms [(PMe(2)Ph)(4)(SO(2))Pt(2)B(10)H(10)] 5, [(PMe(2)Ph)(4)(SO(2))PtPdB(10)H(10)] 12, and [(PMe(2)Ph)(4)(SO(2))Pd(2)B(10)H(10)] 13 with progressively weaker binding of the SO(2) molecule. The uptake and release of gas molecules are accompanied by changes in their absorption spectra. Nanosecond transient absorption spectroscopy clearly shows that the O(2) and CO molecules are liberated from the bimetallic binding site with high quantum yields of about 0.6. For 3, in addition to dioxygen release in the triplet ground state, singlet oxygen O(2)((1)Δ(g)) was also detected with a quantum yield <0.01. In most cases, the release and rebinding of the gas molecules can be cycled with little photodegradation of the compounds. Femtosecond transient absorption spectroscopy further reveals that the photorelease of the O(2) and CO molecules, from 3 and 4 respectively, is an ultrafast process taking place on a time scale of tens of picoseconds. For SO(2), the release is even faster (<1 ps), but only in the case of mixed metal PtPd adducts, most probably because of the metal-metal bonding asymmetry in the mixed metal clusters; for the corresponding symmetric Pt(2) and Pd(2) adducts, 5 and 13, the release of SO(2) is significantly slower (>1 ns). All these compounds may have potential to serve as light-triggered local and instantaneous sources of the studied gases.