XRD structure of two heptacoordinated Mn(II) complexes containing 2,9-dimethyl-1,10-phenanthroline (phen), nitrato and nicotinato bidentate anions: [Mn(phen)(nicot)(NO3)(H2O)]·EtOH·H2O and [Mn(phen)(NO3)2(H2O)]

The XRD structure of two seven-coordinated Mn(II) complexes with the formula [Mn(phen)(nicot)(NO₃)(H₂O)]·EtOH·H₂O (1) and [Mn(phen)(NO₃)₂(H₂O)] (2) are reported. The 2,9-dimethyl-1,10-phenanthroline, nitrato and nicotinato anions act as bidentate ligands, with Mn–N distances of 2.21–2.29 Å and Mn–O distances of 2.17–2.40 Å. In both compounds, the water molecule seems to be the strongest coordinated ligand, with bond distances of 2.139(2) Å in 1 and 2.195(2) Å in 2. The average ratio between coordinated unidentate and bidentate bond lengths less than the unity justifies, from an energetical point of view, the shape of the coordination polyhedra. In the structure of 1, the coordination polyhedron may be best-described as a distorted pentagonal bipyramid with a nitrogen from phenanthroline and the water molecule occupying the apical sites. The polyhedron shape for 2 is close to a square-capped trigonal prism, the capping site being occupied by the water molecule. The crystal structures are built by H-bonded bidimensional sheets piled up by π–π stacking of the partially interpenetrated aromatic moieties of adjacent layers.     

Redistribution reactions of heteroleptic barium iodide derivatives: Synthesis and structures of trans-BaI2(DME)(triglyme), cis-BaI2(DME)(tetraglyme) and [Ba(tetraglyme)2]I2 · C7H8

The reaction between BaI₂ · 2H₂O and NaHFIP [HFIP = OCH(CF₃)₂] in a 1:1 stoichiometry gave the heterometallic compound NaBaI₂(HFIP)(H₂O)(THF)_0.5 (1). Attempts to recrystallize 1 in the presence of N- or O-donor ligands lead to redistribution reactions. Barium iodide adducts such as BaI₂(DME)₃ (2), trans-BaI₂(DME)(triglyme) (3) and cis-BaI₂(DME)(tetraglyme) (4) were isolated with DME as solvent. A similar behavior was observed for the reaction between BaI₂ · 2H₂O and NaTFA (TFA = O₂CCF₃) in a 1:1 stoichiometry in THF, and [Ba(tetraglyme)₂]I₂ · C₇H₈ (6) was isolated in the presence of excess tetraglyme. All compounds have been characterized by elemental analysis, IR and ¹H NMR as well as single crystal X-ray studies for 3, 4 and 6. Compounds 3 and 4 are covalent adducts with eight- and nine-coordinate barium, respectively. Compound 6 is an ionic compound where two tetraglyme ligands wrap the 10-coordinate barium cation in a helical fashion. The presence of DME actually allows the coordination number of barium in the mixed-ligand adducts 3 and 4 to be tuned. The average Ba–O bond lengths (2.80 for 3 to 2.87 Å for 6) reflect the coordination number of the metal. The same observation is valid for the average Ba–I bond distance, 3.442 for 3 vs. 3.536 Å for 4.     

Monomer and cyclic tetramer of copper(II) complexes: Synthesis,characterization and crystal structure determination of [Cu(dm4bt)Cl(Hipht)] and [{Cu(dm4bt)(H2O)(ipht)}4·2H2O]

Copper complexes, [Cu(dm4bt)Cl(Hipht)] (1) and [{Cu(dm4bt)(H₂O)(ipht)}₄·2H₂O] (2) (where dm4bt is 2,2′-dimethyl-4,4′-bithiazole, Hipht is hydrogen isophthalate and ipht is isophthalate) have been synthesized. These two complexes were characterized by IR, UV–Vis and EPR spectroscopy. Moreover; their single-crystal structures were studied by the X-ray diffraction method. Complex 1 has a monomer structure and copper has accepted a distorted square pyramidal structure. Isophthalic acid in 1 lost one of its protons and produced one bidentate carboxylate and one free carboxylic acid. Controlled deprotonation in the presence of ethylene diamine results in self-assemblies of 1 to form a tetramer complex of 2. Complex 2 has two kinds of spatial isomers which are resolved by EPR and X-ray.     

Synthesis and characterization of some novel cadmium(II) complexes with 3-hydroxypicolinic acid (3-OHpicH): Crystal and molecular structures of [CdI(3-OHpic)(3-OHpicH)(H2O)]2, [Cd(3-OHpic)2(H2O)2] and [Cd(3-OHpic)2]n

Cadmium(II) complexes of 3-hydroxypicolinic acid, namely [CdI(3-OHpic)(3-OHpicH)(H₂O)]₂ (1), [Cd(3-OHpic)₂(H₂O)₂] (2) and [Cd(3-OHpic)₂]_n (3) were prepared and characterized by spectroscopic methods (IR, NMR) and their molecular and crystal structures were determined by X-ray crystal structure analysis. Complexes 1 and 2 were prepared in similar reaction conditions using different cadmium(II) salts: cadmium(II) iodide and cadmium(II) acetate dihydrate, respectively, while 3 was prepared by recrystallization of 2 from N,N-dimethylformamide solution. Various coordination modes of 3-OHpicH in 1–3 were established in the solid state: bidentate N,O-chelated mode in 1 and 2, monodentate mode through the carboxylate O atom from zwitterionic ligand in 1 and bidentate N,O-chelated and bridging mode in 3. In the DMF solution of all prepared complexes, only monodentate mode of 3-OHpicH binding to cadmium(II) through the carboxylate O atom was established by ¹H, ¹³C, ¹⁵N and ¹¹³Cd NMR spectroscopy.     

Hydrothermal synthesis, crystal structures and fluorescence properties of three novel frameworks constructed with mixed ligands of isophthalic acid (1,3-BDC) and 2,3-di-2-pyridylquinoxaline (Dpdq): [M(1,3-BDC)(Dpdq)(H2O)m] · nH2O (M = Co, Cd or Zn)

Three novel metal-organic frameworks [M(1,3-BDC)(Dpdq)(H₂O)_m] · nH₂O, (M = Co^II (1), Cd^II (2) or Zn^II (3); m = 0, 1; n = 0, 1, 2, respectively) have been obtained from hydrothermal reactions of three different metal(II) nitrates with the same mixed ligands [isophthalic acid (1,3-BDC) and 2,3-di-2-pyridylquinoxaline (Dpdq)], and structurally characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analyses. Single-crystal X-ray analyses show that each pair of metal ions are bridged by various coordination modes of 1,3-BDC ligands to form left- and right-handed helical chains in 1, linear chains in 2, and double chains in 3, respectively. N-containing flexible ligand Dpdq takes a chelating coordination mode acting as terminal ligand. In the compound 1, adjacent left- and right-handed helical chains are packed through hydrogen bonds to form a two-dimensional (2-D) structure. In the compounds 2 and 3, adjacent chains are further linked by hydrogen bonds and/or π-π stacking interactions to form a three-dimensional (3-D) distorted hexagon meshes supramolecular framework for 2 and a ZnS-related three-dimensional (3-D) topology for 3, respectively. The different structures of compounds 1-3 illustrate that the influence of the metal ions in the self-assembly of polymeric coordination architectures. In addition, compounds 2 and 3 exhibit blue emission in the solid state at room temperature.     

Transition metal complexes with thiosemicarbazide-based ligands. Part LIV. Nickel(II) complexes with pyridoxal semi- (PLSC) and thiosemicarbazone (PLTSC). Crystal and molecular structure of [Ni(PLSC)(H2O)3](NO3)2 and [Ni(PLTSC-H)py]NO3

This paper describes the synthesis of the first Ni(II) complexes with pyridoxal semicarbazone (PLSC), viz. Ni(PLSC)Cl₂ · 3.5H₂O (1), [Ni(PLSC)(H₂O)₃](NO₃)₂ (2), Ni(PLSC)(NCS)₂ · 4H₂O (3), [Ni(PLSC-2H)NH₃] · 1.5H₂O (4), as well as two new complexes with pyridoxal thiosemicarbazone (PLTSC), [Ni(PLTSC-H)py]NO₃ (5) and [Ni(PLTSC-H)NCS] (6). Complexes 1–3 are paramagnetic and have most probably an octahedral structure, for complex 2 this was proved by X-ray diffraction analysis. In contrast, complexes 4–6 are diamagnetic and have a square-planar structure, and in the case of complex 5 this was also confirmed by X-ray structural analysis. In all cases the Schiff bases are coordinated as tridentate ligands with an ONX (X = O, PLSC; X = S, PLTSC) set of donor atoms. With the complexes involving the neutral form of PLSC and the monoanionic form of PLTSC, the PL moiety is in the form of a zwitterion. In addition to the above-mentioned techniques, all the complexes were characterized by measuring their molar conductivities, UV–Vis and partial IR spectra.     

Supramolecular 2D structures in [M(NCS)2(bpe)2(H2O)2] (M = Mn, Fe) systems connected by hydrogen bonds

Here we report the synthesis and characterization by X-ray diffraction, FTIR, UV-Vis and EPR spectroscopies, and the magnetic measurements of two new compounds: [Mn(NCS)₂(bpe)₂(H₂O)₂] (1) and [Fe(NCS)₂(bpe)₂(H₂O)₂] (2) (bpe = 1,2-bis(4-pyridyl)ethylene). Single-crystal structure analyses reveals discrete octahedral metal units that are assembled into 2D sheets through O-Hw?N(bpe) and O-Hw?S(thiocyanate) hydrogen bonds. The intermetallic M?M distances are 6.90 and 6.87 Å for 1 and 2, respectively. Supramolecular architectures are obtained by connections through H-bonds. Slight interactions are observed for compound 2.     

A systematic investigation of the CuCl2/H2mal/phen reaction system (H2mal = malonic acid): Solution and solid state studies of its products

The systematic investigation of the parameter space of the CuCl₂/H₂mal/phen reaction system in MeOH resulted in the isolation of seven different complexes either as mixtures or in pure form, six of which have been structurally characterized. The molar ratios of the reactants and the crystallization methods have been systematically varied, leading to the isolation of compounds [Cu(H₂O)(phen)(mal)] (1), [Cu(MeOH)(phen)(mal)] (2), [Cu₂Li₂Cl₂(phen)₂(mal)₂(MeOH)₄] (3), [Cu₂(phen)₄(mal)][CuCl(phen)(mal)](OH) (4), [CuCl(phen)₂]Cl (5), and [CuCl(phen)(mal)][CuCl(phen)₂][Cu(phen)₂(Hmal)]Cl (6). The coordination versatility of the malonato ligand has been confirmed by the presence of three different coordination modes and its two deprotonation states in compounds 1–6. Solution studies on methanolic solutions of 2–4 and 6 by mass spectrometry revealed the absence of parent ion peak and the presence of fragment ions of low relative abundance not previously found in their crystal structure, thus indicating decomposition and rearrangement/reorganization of the complexes in solution and confirming the dynamic character of their solutions. Compounds 3 and 4 have been also studied in the solid state by EPR spectroscopy and magnetic measurements.     

Reactivity of benzil bis(4-methyl-3-thiosemicarbazone) with cadmium nitrate. Crystal structure of [Cd(LMe2H4)(NO3)2][Cd(LMe2H4)(NO3)(H2O)]NO3 · H2O

The reaction between cadmium nitrate dihydrate and benzil bis(4-methyl-3-thiosemicarbazone), LMe₂H₄, depends on the working conditions. In methanol the reaction gives the novel complex [Cd(LMe₂H₄)(NO₃)₂][Cd(LMe₂H₄)(NO₃)(H₂O)]NO₃ · H₂O (1). Its crystal structure shows the presence of two cadmium atoms with different coordination numbers, seven and eight, and the ligands acting as N₂S₂ neutral molecules. One cadmium has the coordination sphere completed by a bidentate nitrato group and a water molecule, whereas the other one is bonded to two bidentate nitrato groups. Both molecules are joined to one nitrate ion and to an additional water molecule by hydrogen bonds. In the presence of lithium hydroxide, the reaction leads to a binuclear complex with the ligand doubly deprotonated [Cd(LMe₂H₂)]₂ (2). The complexes were characterized by elemental analysis, mass spectrometry, ¹³C and ¹¹³Cd CP/MAS NMR and, in the case of complex 1, by X-ray diffraction.     

Chalcogen-capped ruthenium carbonyl clusters derived from diphosphazane mono- and dichalcogenides of the type X2P(E)N(R)PX2 and X2P(E)N(R)P(E)X2 (E = S or Se)

Reactions of Ru₃(CO)₁₂ with diphosphazane monoselenides Ph₂PN(R)P(Se)Ph₂ [R = (S)-∗CHMePh (L⁴), R = CHMe₂ (L⁵)] yield mainly the selenium bicapped tetraruthenium clusters [Ru₄(μ₄-Se)₂(μ-CO)(CO)₈{μ-P,P-Ph₂PN(R)PPh₂}] (1, 3). The selenium monocapped triruthenium cluster [Ru₃(μ₃-Se)(μ_sb-CO)(CO)₇{κ²-P,P-Ph₂PN((S)-∗CHMePh)PPh₂}] (2) is obtained only in the case of L⁴. An analogous reaction of the diphosphazane monosulfide (PhO)₂PN(Me)P(S)(OPh)₂ (L⁶) that bears a strong π-acceptor phosphorus shows a different reactivity pattern to yield the triruthenium clusters, [Ru₃(μ₃-S)(μ₃-CO)(CO)₇{μ-P,P-(PhO)₂PN(Me)P(OPh)₂}] (9) (single sulfur transfer product) and [Ru₃(μ₃-S)₂(CO)₅{κ²-P,P-(PhO)₂PN(Me)P(OPh)₂}{μ-P,P-(PhO)₂PN(Me)P(OPh)₂}] (10) (double sulfur transfer product). The reactions of diphosphazane dichalcogenides with Ru₃(CO)₁₂ yield the chalcogen bicapped tetraruthenium clusters [Ru₄(μ₄-E)₂(μ-CO)(CO)₈{μ-P,P-Ph₂PN(R)PPh₂}] [R = (S)-∗CHMePh, E = S (6); R = CHMe₂, E = S (7); R = CHMe₂, E = Se (3)]. Such a tetraruthenium cluster [Ru₄(μ₄-S)₂(μ- CO)(CO)₈{μ-P,P-(PhO)₂PN(Me)P(OPh)₂}] (11) is also obtained in small quantities during crystallization of cluster 9. The dynamic behavior of cluster 10 in solution is probed by NMR studies. The structural data for clusters 7, 9, 10 and 11 are compared and discussed.     

New binuclear vanadium(III) and (IV) squarate species: synthesis, structure and characterization of [V(OH)(H2O)2(C4O4)]2·2H2O and (NH4)[(VO)2(OH)(C4O4)2(H2O)3]·3H2O

Two new vanadium squarates have been synthesized, characterized by infrared and thermal behavior and their structures determined by single crystal X-ray diffraction. Both structures are made of discrete, binuclear vanadium entity but in 1, [V(OH)(H₂O)₂(C₄O₄)]₂·2H₂O the vanadium atom is trivalent and the entity is neutral while in 2, (NH₄)[(VO)₂(OH)(C₄O₄)₂(H₂O)₃]·3H₂O, the vanadium atom is tetravalent and the entity is negatively charged, balanced by the presence of one ammonium ion. Both molecular anions are bridged by two terminal μ₂ squarate ligands. 1 crystallizes in the triclinic system, space group P-1, with lattice constants a=7.5112(10) Å, b=7.5603(8) Å, c=8.2185(8) Å, α=106.904(8)°, β=94.510(10)°, γ=113.984(9)° while 2 crystallizes in the monoclinic system, space group C2/c, with a=14.9340(15) Å, b=6.4900(9) Å, c=17.9590(19) Å and β=97.927(12)°. From the magnetic point of view, V(III) binuclear species show ferromagnetic interactions at low temperatures. However, no anomalies pointing to magnetic ordering are observed down to 2 K.     

Mixed-metal single-molecule magnets: Syntheses, structure, and magnetic properties of [Mn8Fe4O12(O2CR)16(H2O)4] (R = CH2Cl, CH2Br, CHCl2)

Three mixed-metal single-molecule magnets containing [Mn₈Fe₄O₁₂]¹⁶⁺ cores are synthesized and characterized. The reaction of FeCl₂·4H₂O with KMnO₄ and RCOOH (R = CH₂Cl, CH₂Br) in H₂O gives [Mn₈Fe₄O₁₂(O₂CR)₁₆(H₂O)₄] (R = CH₂Cl (1), CH₂Br (2)) in yields of 43% and 40%, respectively. Treatment of complex 1 with an excess of CHCl₂COOH in CH₂Cl₂ gives [Mn₈Fe₄O₁₂(O₂CCHCl₂)₁₆(H₂O)₄]·CH₂Cl₂·10H₂O (3·CH₂Cl₂·10H₂O) in a yield of 83%. The X-ray structure analysis reveals that all three complexes consist of a trapped-valence dodecanuclear core comprising 4Mn^III, 4Fe^III, and 4Mn^IV ions. DC magnetic susceptibility and magnetization measurements indicate that all three complexes exhibit intramolecular antiferromagnetic interaction, resulting in an S = 4 ground state. In addition, frequency-dependent out-of-phase AC magnetic susceptibility signals at low temperature for complexes 1, 2, and 3 are indicative of their single-molecule magnetism behavior.     

Reactions of ruthenium benzylidenes with H2O to give benzaldehyde and (aqua)ruthenium complex

The second generation of Grubbs type catalyst, (PCy₃)(H₂IMes)Cl₂RuCHPh (1) undergoes the Cl replacement with CH₃CN to give cationic ruthenium carbene complexes, [(RCN)₃(H₂IMes)RuCHPh](OTf)₂ (2, R = CH₃ (a), Ph (b)) in the presence of AgOTf. The reaction of 2a with H₂O in the presence of CH₃CN gives (aqua)ruthenium complex, [Ru(H₂IMes)(NCCH₃) ₄(H₂O)](OTf)₂ (3) and benzaldehyde. Benzaldehyde is also observed in the reaction of 1 with H₂O. Plausible reaction pathways are suggested for the degradation of ruthenium benzylidenes to give benzaldehyde on the basis of the isotope labeling experiments.     

A series of three-dimensional coordination polymers with general formula [{Ln(H2O)n}{Re6Te8(CN)6}] · xH2O (Ln = Eu,Gd, Tb,Dy, Ho,Er, Tm,Yb; n = 3, 4, x = 0, 2.5)

A series of new compounds containing rare earth cations (Eu to Yb) and paramagnetic cluster anion [Re₆Te₈(CN)₆]³⁻ was prepared and investigated. The X-ray structural analyses have revealed that the compounds [{Ln(H₂O)₄}{Re₆Te₈(CN)₆}] · 2.5H₂O; Ln = Eu (1), Tb (3), Dy (4), Ho (5), Er (6), Tm (7), [{Gd(H₂O)₃}{Re₆Te₈(CN)₆}] · 2.5H₂O (2) and [{Yb(H₂O)₄}{Re₆Te₈(CN)₆}] (8) are three-dimensional polymers based on Re–CN–Ln interactions. Measurements of magnetic susceptibility for 2 and 5 showed that effective magnetic moment (at 300 K) was 8.13 μ_B for compound 2 and 10.79 μ_B for compound 5 with weak antiferromagnetic ordering appeared at low temperatures.     

Crystal structures of [Ru(terpy)(HPB)(H2O)](PF6)2 and [Ru(terpy)(HPB)(2-picoline)](PF6) and the kinetics studies of the aqua ligand substitution by pyridine and substituted pyridines

The crystal structures of [Ru(terpy)(HPB)(H₂O)](PF₆)₂, 1, and [Ru(terpy)(HPB)(2-picoline)](PF₆), 2, (where terpy = 2,2′:6′,2′′-terpyridine and HPB = 2-(2′-hydroxyphenyl)-benzoxazole) have been determined. Both structures show slightly distorted octahedral coordination around the ruthenium center. In complex 1, the imine nitrogen of the HPB ligand occupies an axial position and is trans to the aqua ligand whereas in complex 2, the imine nitrogen is trans to the nitrogen of the 2-picoline ligand. The Ru-N(2-picoline) bond distance is much longer than the other Ru-N bonds in the complex due to steric effects from the methyl group of 2-picoline. In both complexes, the phenolate oxygen of the HPB ligand is in the equatorial position and trans to the center nitrogen of the terpyridine. The reaction of [Ru(terpy)(HPB)(H₂O)](PF₆)2 with pyridine and its analogs, 2-picoline and 4-picoline in dichloromethane was monitored spectrophotometrically. There is an initial reduction of the [Ru(III)-H₂O] complex to [Ru(II)-H₂O] complex prior to the substitution of the aqua ligand. The values of the activation parameters indicate that the substitution of the aqua ligand by pyridine, 2-picoline and 4-picoline follow an associative mechanism.     

Trifluoroacetylacetonate rhodium(III) methyl complexes, cis-[Rh(TFA)(PPh3)2(CH3)(L)][BPh4] and cis-[Rh(TFA)(PPh3)2(CH3)(I)] (L = CH3CN, NH3, pyridine), in comparison with their acetylacetonate analogs

The oxidative addition of CH₃I to planar rhodium(I) complex [Rh(TFA)(PPh₃)₂] in acetonitrile (TFA is trifluoroacetylacetonate) leads to the formation of cationic, cis-[Rh(TFA)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] (1), or neutral, cis-[Rh(TFA)(PPh₃)₂(CH₃)(I)] (4), rhodium(III) methyl complexes depending on the reaction conditions. 1 reacts readily with NH₃ and pyridine to form cationic complexes, cis-[Rh(TFA)(PPh₃)₂(CH₃)(NH₃)][BPh₄] (2) and cis-[Rh(TFA)(PPh₃)₂(CH₃)(Py)][BPh₄] (3), respectively. Acetylacetonate methyl complex of rhodium(III), cis-[Rh(Acac)(PPh₃)₂(CH₃)(I)] (5), was obtained by the action of NaI on cis-[Rh(Acac)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] in acetone at −15 °C. Complexes 1-5 were characterized by elemental analysis, ³¹P{¹H}, ¹H and ¹⁹F NMR. For complexes 2, 3, 4 conductivity data in acetone solutions are reported. The crystal structures of 2 and 3 were determined. NMR parameters of 1-5 and related complexes are discussed from the viewpoint of their isomerism.     

Aqueous organometallic chemistry. 3. Catalytic hydride transfer reactions with ketones and aldehydes using [Cp∗Rh(bpy)(H2O)](OTf)2 as the precatalyst and sodium formate as the hydride source: Kinetic and activation parameters, and the significance of steric and electronic effects

The reaction of a precatalyst, [Cp∗Rh(bpy)(H₂O)](OTf)₂ (1), with sodium formate provided the hydride complex, [Cp∗Rh(bpy)(H)]⁺ (2), in situ, at pH 7.0, which was then evaluated in an aqueous, catalytic hydride transfer process with water soluble substrates that encompass 2-pentanone (3), cyclohexanone (4), acetophenone (5), propionaldehyde (6), benzaldehyde (7), and p-methoxybenzaldehyde (8). The initial rates, r_i, of appearance of the reduction product alcohols at 23 °C provided a relative rate scale: 8 > 7 ≈ 6 > 5 > 4 > 3, while the effect of concentration of substrate, precatalyst, and sodium formate on r_i, using 7 as an example, implicates [Cp∗Rh(bpy)(H)]⁺ formation as the rate-limiting step. The experimental kinetic rate expression was found to be: d[alcohol]/dt = k_cat[1][HCO₂Na]; substrate being pseudo zero order in water. The steric effects were also analyzed and appeared to be of less importance intra both the ketone and aldehyde series, but an inter series comparison appeared to show that the aldehydes had less of a steric effect on the initial rate, i.e., 7 > 4 by a factor of 3.6, while the aldehyde series appeared to have some moderate electronic influence on rates, presumably via electron donation to increase binding to the Cp∗Rh metal ion center, in accordance with these proposed concerted binding/hydride transfer reactions. A proposed catalytic cycle will also be presented.     

The CO and CS bond cleavage in carbon dioxide and tolyl isothiocyanate by reactions with the Mo(0) tetraphosphine complex [Mo{meso-o-C6H4(PPhCH2CH2PPh2)2}(Ph2PCH2CH2PPh2)]

A Mo(0) complex containing a new tetraphosphine ligand [Mo(P₄)(dppe)] (1; P₄ = meso-o-C₆H₄(PPhCH₂CH₂PPh₂)₂, dppe = Ph₂PCH₂CH₂PPh₂) reacted with CO₂ (1 atm) at 60 °C in benzene to give a Mo(0) carbonyl complex fac-[Mo(CO)(η³-P₄O)(dppe)] (2), where the O abstraction from CO₂ by one terminal P atom in P₄ takes place to give the dangling P(O)Ph₂ moiety together with the coordinated CO. On the other hand, reaction of 1 with TolNCS (Tol = m-MeC₆H₄) in benzene at 60 °C resulted in the incorporation of three TolNCS molecules to the Mo center, forming a Mo(0) isocyanide-isothiocyanate complex trans,mer-[Mo(TolNC)₂(η²-TolNCS)(η³-P₄S)] (4), where the S abstraction occurs from two TolNCS molecules by P₄ and dppe to give the η³-P₄S ligand and free dppeS, respectively, together with two coordinated TolNC molecules. The remaining site of the Mo center is occupied by the third TolNCS ligating at the CS bond in an η²-manner. The X-ray analysis has been undertaken to determine the detailed structures for 2 and 4.