Reactions of laser-ablated zinc and cadmium atoms with CO: infrared spectra of the Zn(CO)x (x = 1-3), CdCO-, and Cd(CO)2 molecules in solid neon

Reactions of laser-ablated zinc and cadmium atoms with carbon monoxide molecules in solid neon have been investigated using matrix-isolation infrared spectroscopy. Based on the isotopic substitution, absorptions at 1852.2, 1901.9, 1945.9, and 1995.2 cm(-1) are assigned to the C-O stretching vibrations of the ZnCO, Zn(CO)(2), and Zn(CO)(3) molecules. Absorptions at 1735.8, 1961.3, and 2035.7 cm(-1) are assigned to the C-O stretching vibrations of the CdCO(-) and Cd(CO)(2) molecules. In contrast with the previous argon experiments, more species and more valuable information about the reaction of zinc and cadmium atoms with CO have been obtained in solid neon. Density functional theory calculations have been performed on these zinc and cadmium carbonyls. The agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts substantiates the identification of these carbonyls from the matrix infrared spectrum. The present experiments also reveal that zinc is more reactive with CO than cadmium.     

Reactions of gold atoms and small clusters with CO: Infrared spectroscopic and theoretical characterization of Au(n)CO (n = 1-5) and Au(n)(CO)2 (n = 1, 2) in solid argon

Laser-ablated Au atoms have been co-deposited with CO molecules in solid argon to produce gold carbonyls. In addition to the previously reported Au(CO)n (n = 1, 2) and Au2(CO)2 molecules, small gold cluster monocarbonyls Au(n)CO (n = 2-5) are formed on sample annealing and characterized using infrared spectroscopy on the basis of the results of the isotopic substitution and CO concentration change and comparison with theoretical predictions. Of particular interest is that the mononuclear gold carbonyls, Au(CO)n (n = 1, 2), are favored under the experimental conditions of higher CO concentration and lower laser energy, whereas the yields of the gold cluster carbonyls, Au(n)CO (n = 2-5) and Au2(CO)2, remarkably increase with lower CO concentration and higher laser power. Density functional theory (DFT) calculations have been performed on these molecules and the corresponding small naked gold clusters. The identities of these gold carbonyls Au(n)CO (n = 1-5) and Au(n)(CO)2 (n = 1, 2) are confirmed by the good agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts.     

Oxidation of carbon monoxide on group 11 metal atoms: matrix-isolation infrared spectroscopic and density functional theory study

Laser-ablated Cu, Ag, and Au atoms react with CO and O2 mixture in solid argon to produce carbonyl metal oxides, (O2)Cu(CO)(n) (n = 1, 2), (eta(1)-OO)MCO (M = Ag, Au), OCAuO2CO, and OAuCO, as well as group 11 metal carbonyls and oxides. These carbonyl metal oxides are characterized using infrared spectroscopy on the basis of the results of the isotopic substitution and the CO concentration change. Density functional theory (DFT) calculations have been performed on these molecules. The identifications of these carbonyl metal oxides are confirmed by the good agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts. Carbon dioxide is eliminated from these carbonyl metal oxides upon UV irradiation, providing the evidence for the oxidation of carbon monoxide on group 11 metal atoms. The present experiments also reveal that the reactivity of copper toward CO is prior to O2, and the reactivity of silver toward O2 is prior to CO, whereas the reactivity of gold toward CO is comparable to O2.     

Observation of the lead carbonyls, PbnCO(n=1-4): reactions of lead atoms and small clusters with carbon monoxide in solid argon

Reactions of laser-ablated Pb atoms with CO molecules in solid argon lead to the formation of the lead carbonyls, PbnCO (n=1-4), using matrix-isolation infrared spectroscopy. Absorption at 2027.7 cm(-1) is assigned to C-O stretching mode of the PbCO product, which appears and increases on annealing, disappears on broadband irradiation, and recovers on further annealing. Small lead cluster mono-carbonyls PbnCO (n=2-4) are also observed in the present infrared spectra. Based on the results of stepwise annealing and the comparison with theoretical predictions, the absorptions at 1915.5, 1923.8, and 2042.8 cm(-1) are assigned to Pb2CO, Pb3CO, and Pb4CO, respectively. Bridging CO is found in Pb2CO or Pb3CO, whereas terminal CO in Pb4CO. The density functional theory calculations have been performed on these molecules and small naked lead clusters. The good agreement between experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts provides strong support for the identifications of these lead mono-carbonyls PbnCO (n=1-4). Furthermore, energetic analysis for the possible reactions of lead atoms with CO molecules is also given.     

Reactions of laser-ablated La and Y atoms with CO: matrix infrared spectra and DFT calculations of the M(CO)x and MCO+ (M = La, Y; x = 1-4) molecules

Reactions of laser-ablated lanthanum and yttrium atoms with carbon monoxide molecules in solid neon have been investigated using matrix-isolation infrared spectroscopy. The M(CO)x and MCO+ (M = La, Y; x = 1-4) molecules have been formed and identified on the basis of isotopic shifts, mixed isotopic splitting patterns, and CCl4-doping experiments. Density functional theory calculations have been performed on these lanthanum and yttrium carbonyls. The agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts substantiates the identification of these carbonyls from the matrix infrared spectrum. The present study reveals that the C-O stretching vibrational frequencies of MCO+ decrease from Sc to La, which indicates an increasing in metal d orbital --> CO pi* back-donation in this series.     

Reactions of germanium atoms and small clusters with CO: experimental and theoretical characterization of Ge(n)CO (n = 1-5) and Ge2(CO)2 in solid argon

Reactions of germanium atoms and small clusters with carbon monoxide molecules in solid argon have been studied using matrix isolation infrared absorption spectroscopy. Besides the previously reported GeCO monocarbonyl, the Ge2(CO)2 and Ge(n)CO (n = 2-5) carbonyl molecules are formed spontaneously on annealing and are characterized on the basis of isotopic substitution and theoretical calculations. It is found that Ge2CO, Ge3CO, and Ge5CO are bridge-bonded carbonyl compounds, whereas Ge2(CO)2 and Ge4CO are terminal-bonded carbonyl molecules.     

Infrared spectroscopic and theoretical studies on the reactions of copper atoms with carbon monoxide and nitric oxide molecules in rare-gas matrices

Reactions of laser-ablated Cu atoms with CO and NO mixtures in solid argon and neon have been investigated using matrix-isolation infrared spectroscopy. Copper carbonyls and copper nitrosyls have been observed, whereas copper carbonyl nitrosyl complexes are absent from the present experiments. New products, (CuCO)2, [NO]Cu[NO], Cu2(mu2-NO), and Cu(NO)2Cu, have been formed in the copper experiments and characterized using infrared spectroscopy on the basis of the results of the isotopic shifts, mixed isotopic splitting patterns, stepwise annealing, the change of reagent concentration and laser energy, and comparison with theoretical predictions. Density functional theory calculations have been performed on these copper carbonyls and copper nitrosyls, which support the identification of these products from the matrix infrared spectrum. A plausible reaction mechanism has been proposed to account for the formation of copper carbonyls and copper nitrosyls. Similar matrix experiments with Ag and Au produce no new species.     

Ring-opening polymerization of coordination complexes: silver(I) complexes with bis(amidopyridine) ligands derived from thiophene

The thiophene-based bis(N-methylamido-pyridine) ligand SC4H2-2,5-{C(=O)N(Me)-4-C5H4N}2 reacts with silver(I) salts AgX to give 1 : 1 complexes, which are characterized in the solid state as the macrocyclic complexes [Ag(2){SC4H2-2,5-(CONMe-4-C5H4N)2}2][X]2, which have the cis conformation of the C(=O)N(Me) group, when X = CF3CO2, NO3, or CF3SO3 but as the polymeric complex [Ag(n){SC4H2-2,5-(CONMe-4-C5H4N)2}n][X]n, with the unusual trans conformation of the C(=O)N(Me) group, when X = PF6. The bis(amido-pyridine) ligand SC4H2-2,5-{C(=O)NHCH2-3-C5H4N}2 reacts with silver(I) trifluoroacetate to give the polymeric complex [Ag(n){SC4H2-2,5-(CONHCH2-3-C5H4N)2}n][X]n, X = CF3CO2. The macrocyclic complexes contain transannular argentophilic secondary bonds. The polymers self assemble into sheet structures through interchain C=O...Ag and S...Ag bonds in [Ag(n){SC4H2-2,5-(CONMe-4-C5H4N)2}n][PF6]n and through Ag...Ag, C=O...Ag and Ag...O(trifluoroacetate)...HN secondary bonds in [Ag(n){SC4H2-2,5-(CONHCH2-3-C5H4N)2}n][CF3CO2]n.     

Infrared spectra of the M(NO)n (M = Sn, Pb; n = 1, 2) and PbNO- molecules

Reactions of laser-ablated tin and lead atoms with nitric oxide molecules in solid argon and neon have been investigated using matrix-isolation infrared spectroscopy. In the argon experiments, absorptions at 1560.1, 1625.8, and 1486.7 cm(-1) are assigned to the N-O stretching vibrations of the SnNO and Sn(NO)2 molecules, and absorptions at 1541.9, 1630.0, 1481.8, and 1457.5 cm(-1) are assigned to the N-O stretching vibrations of the PbNO, Pb(NO)2, and PbNO- molecules on the basis of isotopic shifts and splitting patterns. The present neon experiments only produce neutral tin and lead mononitrosyls. Density functional theory calculations have been performed on these tin and lead nitrosyls. The good agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts substantiates the identification of these nitrosyls from the matrix infrared spectra.     

Matrix infrared spectroscopic and theoretical of the difluoroamino metal fluoride molecules: F2NMF (M = Cu, Ag, Au)

The difluoroamino coinage metal fluoride molecules F(2)NMF (M = Cu, Ag, Au) have been made via spontaneous reactions of coinage metals and NF(3) in solid argon and neon matrixes during sample annealing without formation of the M(NF(3)) complexes. Comparisons between the matrix infrared spectra and the density functional frequency calculations provide strong support for identification of the F(2)NMF molecules, which are found to have doublet ground states with C(2v) or near C(2v) geometries. The F(2)NCuF molecule can isomerize to the less stable FNCuF(2) isomer upon UV-visible irradiation, while no similar reactions were observed for the silver and gold species. The M-N bonds in the F(2)NMF molecules are stronger than those in the FNMF(2) isomers with the Ag-N bond being longest and weakest in both cases.     

Reactions of silicon atoms and small clusters with CO: experimental and theoretical characterization of SinCO (n=1-5), Si2(CO)2, c-Si2(mu-O)(mu-CSi), and c-Si2(mu-O)(mu-CCO) in solid argon

Reactions of silicon atoms and small clusters with carbon monoxide molecules in solid argon have been studied using matrix isolation infrared absorption spectroscopy. In addition to the previously reported SiCO monocarbonyl, Si(2)(CO)(2) and Si(n)CO (n=2-5) carbonyl molecules were formed spontaneously on annealing and were characterized on the basis of isotopic substitution and theoretical calculations. It was found that Si(2)CO, Si(3)CO, and Si(5)CO are bridge-bonded carbonyl compounds, whereas Si(4)CO is a terminal-bonded carbonyl molecule. The Si(2)(CO)(2) and Si(3)CO molecules photochemically rearranged to the more stable c-Si(2)(mu-O)(mu-CCO) and c-Si(2)(mu-O) (mu-CSi) isomers where Si(2) is inserted into the CO triple bond.     

配合物[Ag(chlsp)2](F3CCOO)的合成，谱学和晶体结构

A silver(Ⅰ) complex [Ag(chlsp)₂](CF₃CO₂)， (chlsp=(E)-4-(4-chlorostyryl) pyridine)， was synthesized by the reaction between AgCF₃CO₂ and chlsp in the anhydrous enthnol. The crystal structure of [Ag(chlsp)₂](CF₃CO₂) was characterized by elemental analysis， IR and determined by using single crystal X-ray diffraction. The result shows that the complex crystallize in triclinic system， with space group P1， a=0.109 7(2) nm， b=0.111 7(2) nm， c=0.117 2(2) nm， α=73.60(3)°， β=85.03(3)°， γ=81.82(3)°， V=0.136 2(4) nm³， Z=2. The moleculars are connected by Ag…Ag and Ag…Cl interactions， resulting in a three-dimensional network. CCDC: 631131.     

Silver cages with encapsulated acetylenediide as building blocks for hydrothermal synthesis of supramolecular complexes with n-cyanopyridine and pyridine-n-carboxamide (n=3, 4)

New silver(i) double salts (Ag(2)C(2))(AgCF(3)CO(2))(8)(3-pyCONH(2))(2)(H(2)O)(4) (1), [(Ag(2)C(2))(AgCF(3)CO(2))(4)(4-pyCONH(2))(H(2)O)].H(2)O (2), (Ag(2)C(2))(AgCF(3)CO(2))(6)(3-pyCONH(2))(4) (3), (Ag(2)C(2))(AgCF(3)CO(2))(6)(3-pyCN)(2) (4) and (Ag(2)C(2))(AgCF(3)CO(2))(4)(4-pyCN)(2) (5) (n-pyCONH(2) is pyridine-n-carboxamide, n-pyCN is n-cyanopyridine; n=3, 4) have been synthesized by the hydrothermal method. All five compounds contain polyhedral silver(i) cages each encapsulating a C(2)(2-) dianion. Compounds 1, 3 ,4 and 5 exhibit three-dimensional structures, whereas compound 2 is a two-dimensional network. The structure of 1 is constructed from the linkage of a branched-tree architecture via hydrogen bonds. Unlike 4 and 5, which involve the connection of n-cyanopyridine (n=3, 4) with silver columns, 3 results from the linkage of discrete silver cages via pyridine-3-carboxamide.     

(Eta-C5H4R)Fe(CO)2X], X = Cl, Br, I, NO3, CO2Me and [(eta-C5H4R)Fe(CO)3]+, R = (CH2)nCO2Me (n = 0-2), and CO2CH2CH2OH: a new group of CO-releasing molecules

A new group of CO-releasing molecules, CO-RMs, based on cyclopentadienyl iron carbonyls have been identified. X-Ray structures have been determined for [(eta-C(5)H(4)CO(2)Me)Fe(CO)(2)X], X = Cl, Br, I, NO(3), CO(2)Me, [(eta-C(5)H(4)CO(2)Me)Fe(CO)(2)](2), [(eta-C(5)H(4)CO(2)CH(2)CH(2)OH)Fe(CO)(2)](2) and [(eta-C(5)H(4)CO(2)Me)Fe(CO)(3)][FeCl(4)]. Half-lives for CO release, (1)H, (13)C, and (17)OC NMR and IR spectra have been determined along with some biological data for these compounds, [(eta-C(5)H(4)CO(2)CH(2)CH(2)OH)Fe(CO)(3)](+) and [[eta-C(5)H(4)(CH(2))(n)CO(2)Me]Fe(CO)(3)](+), n = 1, 2. More specifically, cytotoxicity assays and inhibition of nitrite formation in stimulated RAW264.7 macrophages are reported for most of the compounds analyzed. [(eta-C(5)H(5))Fe(CO)(2)X], X = Cl, Br, I, were also examined for comparison. Correlations between the half-lives for CO release and spectroscopic parameters are found within each group of compounds, but not between the groups.     

Preparation and characterization of the argentates: [Ag[P(CF(3))(2)](2)](-), [Ag[(micro-P(CF(3))(2))M(CO)(5)](2)](-) (M = Cr, W), and [Ag[(micro-P(C(6)F(5))(2))W(CO)(5)](2)](-): X-ray crystal structure of [K(18-crown-6)][Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)

The first example of a mononuclear diphosphanidoargentate, bis[bis(trifluoromethyl)phosphanido]argentate, [Ag[P(CF(3))(2)](2)](-), is obtained via the reaction of HP(CF(3))(2) with [Ag(CN)(2)](-) and isolated as its [K(18-crown-6)] salt. When the cyclic phosphane (PCF(3))(4) is reacted with a slight excess of [K(18-crown-6)][Ag[P(CF(3))(2)](2)], selective insertion of one PCF(3) unit into each silver phosphorus bond is observed, which on the basis of NMR spectroscopic evidence suggests the [Ag[P(CF(3))P(CF(3))(2)](2)](-) ion. On treatment of the phosphane complexes [M(CO)(5)PH(CF(3))(2)] (M = Cr, W) with [K(18-crown-6)][Ag(CN)(2)], the analogous trinuclear argentates, [Ag[(micro-P(CF(3))(2))M(CO)(5)](2)](-), are formed. The chromium compound [K(18-crown-6)][Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)] crystallizes in a noncentrosymmetric space group Fdd2 (No. 43), a = 2970.2(6) pm, b = 1584.5(3) pm, c = 1787.0(4), V = 8.410(3) nm(3), Z = 8. The C(2) symmetric anion, [Ag[(micro-P(CF(3))(2))Cr(CO)(5)](2)](-), shows a nearly linear arrangement of the P-Ag-P unit. Although the bis(pentafluorophenyl)phosphanido compound [Ag[P(C(6)F(5))(2)](2)](-) has not been obtained so far, the synthesis of its trinuclear counterpart, [K(18-crown-6)][Ag[(micro-P(C(6)F(5))(2))W(CO)(5)](2)], was successful.     

Gas phase synthesis, structure and unimolecular reactivity of silver iodide cluster cations, Ag(n)I(m)(+) (n = 2-5, 0 < m < n)

Multistage mass spectrometry (MS(n)) experiments reveal that gas phase silver iodide cluster cations, Ag(n)I(m)(+), are readily built up in a stepwise fashion via ion-molecule reactions between mass selected silver (Ag(3)(+) and Ag(5)(+)) or silver hydride (Ag(2)H(+) and Ag(4)H(+)) cluster cations and allyl iodide, in contrast to their reactions with methyl iodide, which solely result in ligation of the clusters. The stoichiometries of these clusters range from 1 < or = n < or = 5 and 1 < or = m < or = 4, indicating the formation of several new subvalent silver iodide clusters. Collision induced dissociation (CID) experiments were carried out on each of these clusters to shed some light on their possible structures. The products arising from CID of the Ag(n)I(m)(+) clusters are highly dependent on the stoichiometry of the cluster. Thus the odd-electron clusters Ag(4)I(2)(+) and Ag(5)I(+) fragment via loss of a silver atom. In contrast, the even-electron cluster ions all fragment via loss of AgI. In addition, Ag(2)I(2) loss is observed for the Ag(4)I(3)(+) and Ag(5)I(2)(+) clusters, while loss of Ag(3)I(3) occurs for the stoichiometric Ag(5)I(4)(+) cluster. DFT calculations were carried out on these Ag(n)I(m)(+) clusters as well as the neutrals associated with the ion-molecule and CID reactions. A range of different isomeric structures were calculated and their structures are described. A noteworthy aspect is that ligation of these silver clusters by I can have a profound effect on the geometry of the silver cluster. For example, D(3h) Ag(3)(+) becomes C(2v) Ag(3)I(+), which in turn becomes C(2h) Ag(3)I(2)(+). Finally, the DFT predicted thermochemistry supports the different types of reaction channels observed in the ion-molecule reactions and CID experiments.     

Vapochromic behavior of {Ag2(Et2O)2[Au(C6F5)2]2}n with volatile organic compounds

The vapochromic behaviors of {Ag2L2[Au(C6F5)2]2}n (L = Et2O (1), Me2CO (2), THF (3), CH3CN (4)) were studied. {Ag2L2[Au(C6F5)2]2}n (L = Et2O (1)) was synthesized by the reaction of [Bu4N][Au(C6F5)2] with AgOClO3 in 1:1 molar ratio in CH2Cl2/Et2O (1:2). 1 was used as starting material with THF to form {Ag2L2[Au(C6F5)2]2}n (L = THF (3)). 3 crystallizes in the monoclinic space group C2/c and consists of tetranuclear units linked together via aurophilic contacts resulting in the formation of a 1D polymer that runs parallel to the crystallographic z axis. The gold(I) atoms are linearly coordinated to two pentafluorophenyl groups and display additional Au...Ag close contacts within the tetranuclear units with distances of 2.7582(3) and 2.7709(3) A. Each silver(I) center is bonded to the two oxygen atoms of the THF molecules with a Ag-O bond distance of 2.307(3) A. TGA analysis showed that 1 loses two molecules of the coordinated solvent per molecular unit (1st one: 75-100 degrees, second one: 150-175 degrees C), whereas 2, 3, and 4 lose both volatile organic compounds (VOCs) and fluorinated ligands in a less well defined manner. Each complex loses both the fluorinated ligands and the VOCs by a temperature of about 325 degrees C to give a 1:1 gold/silver product. X-ray powder diffraction studies confirm that the reaction of vapors of VOCs with 1 in the solid state produce complete substitution of the ether molecules by the new VOC. The VOCs are replaced in the order CH3CN > Me2CO > THF > Et2O, with the ether being the easiest to replace. {Ag2(Et2O)2[Au(C6F5)2]2}n and {Ag2(THF)2[Au(C6F5)2]2} n both luminesce at room temperature and at 77 K in the solid state. Emission maxima are independent of the excitation wavelength used below about 500 nm. Emission maxima are obtained at 585 nm (ether) and 544 nm (THF) at room temperature and at 605 nm (ether) and 567 nm (THF) at 77 K.     

Strongly cluster size dependent reaction behavior of CO with O2 on free silver cluster anions

Reactions of free silver anions Agn- (n = 1 - 13) with O2, CO, and their mixtures are investigated in a temperature controlled radio frequency ion trap setup. Cluster anions Agn- (n = 1 - 11) readily react with molecular oxygen to yield AgnOm- (m = 2, 4, or 6) oxide products. In contrast, no reaction of the silver cluster anions with carbon monoxide is detected. However, if silver cluster anions are exposed to the mixture of O2 and CO, new reaction products and a pronounced, discontinuous size dependence in the reaction behavior is observed. In particular, coadsorption complexes Agn(CO)O2- are detected for cluster sizes with n = 4 and 6 and, the most striking observation, in the case of the larger odd atom number clusters Ag7-, Ag9-, and Ag11-, the oxide product concentration decreases while a reappearance of the bare metal cluster signal is observed. This leads to the conclusion that carbon monoxide reacts with the activated oxygen on these silver clusters and indicates the prevalence of a catalytic reaction cycle.     

Theoretical study on homoleptic mononuclear and binuclear ruthenium carbonyls Ru(CO) n (n= 3–5) and Ru2(CO) n (n = 8, 9)

Science China Chemistry - Homoleptic mononuclear and binuclear ruthenium carbonyls Ru(CO) n (n = 3–5) and Ru2(CO) n (n = 8,9) have been investigated using density functional theory. Sixteen...     

On the noble-gas-induced intersystem crossing for the CUO molecule: experimental and theoretical investigations of CUO(Ng)n (Ng = Ar, Kr, Xe; n = 1, 2, 3, 4) complexes in solid neon

Uranium atoms excited by laser ablation react with CO in excess neon to produce the novel CUO molecule, which forms distinct Ng complexes (Ng = Ar, Kr, Xe) when the heavier noble gases are added. The CUO(Ng) complexes are identified through CO isotopic and Ng substitution on the neon matrix infrared spectra and by comparison to DFT frequency calculations. The U-C and U-O stretching frequencies of CUO(Ng) complexes are slightly red-shifted from frequencies for the (1)Sigma(+) CUO ground state, which identifies singlet ground state CUO(Ng) complexes. In solid neon the CUO molecule is also a complex CUO(Ne)(n), and the CUO(Ne)(n-1)(Ng) complexes are likewise specified. The next singlet CUO(Ne)(x)(Ng)(2) complexes in excess neon follow in like manner. However, the higher CUO(Ne)(x)(Ng)(n) complex (n = 3, 4) stretching modes approach pure argon matrix CUO(Ar)(n) values and isotopic behavior, which are characterized as triplet ground state complexes by DFT frequency calculations. This work suggests that the singlet-triplet crossing occurs with 3 Ar, 3 Kr, or 4 Xe and a balance of Ne atoms coordinated to CUO in the neon matrix host.