Encapsulation of N-containing compounds in a new hydrophilic Cd-based crystalline sponge via coordinative alignment method

The crystalline sponge method (CSM) is a technology which allows precise molecular determination of non-crystalline compounds, without the need to crystallise them independently, by soaking them in a crystalline metal–organic framework (MOF). To expand the CSM to a wider range of guest molecules, the development of a new crystalline sponge is essential. In this study a new Cd-based MOF {[Cd7(4,4′4′′-[1,3,5-benzenetriyltris(carbonylimino)]-trisbenzoato)4(μ3-OH)2(H2O)4(DMF)4]·(solvent)x}n was synthesized and investigated as an alternative crystalline sponge (2). Sponge 2 demonstrated versatility in solvent stability compared to the well-studied [{(ZnI2)3(tris(4-pyridyl)-1,3,5-triazine)2·x(CHCl3)}n] (1) and was stable in the presence of polar aprotic, polar protic solvents and Lewis bases. Inclusion complexes with three solvents, acetonitrile, acetone, and isopropanol were prepared. These guest molecules were fixed in the pore via hydrogen bonding confirming the hydrophilic pore environment of sponge 2. Notably, sponge 2 also demonstrated the ability to accommodate N-containing compounds such as pyridine, 3,5-lutidine, and 4-aminopyridine via the coordinative alignment method (CAL). A study was conducted to compare the ability of sponge 2 and related pyridine containing sponge 3 by encapsulating the same pair of guests: N,N-dimethylaniline and propiophenone

Cleavage of Ge–S and C–H bonds in the reaction of electron-deficient [Os₃(CO)₈(μ-H)(μ₃-Ph₂PCH₂P(Ph)C₆H₄)] with Ph₃GeSPh: Generation of thiophenol derivatives [Os₃(CO)₈(μ-H)(μ-SPh)(μ-dppm)] and [Os₃(CO)₇(μ-H)(μ-SPh)(μ₃-SC₆H₄)(μ-dppm)]

Heating the electron-deficient [Os₃(CO)₈(μ-H)(μ₃-Ph₂PCH₂P(Ph)C₆H₄)] (1) and Ph₃GeSPh in benzene at 80 °C led to the thiolato bridged compounds, [Os₃(CO)₈(μ-H)(μ-SPh)(μ-dppm)] (2) and [Os₃(CO)₇(μ-H)(μ-SPh)(μ₃-SC₆H₄)(μ-dppm)] (3), formed by cleavage of Ge–S and C–S bonds of the ligand, in 40% and 17% yields, respectively. Both compounds 2 and 3 have been characterized by a combination of elemental analysis, infrared and ¹H NMR spectroscopic data together with single crystal X-ray crystallography. Compound 3 contains an open triangle of osmium atoms bridged by a SPh and SC₆H₄ ligands on opposite sides of the cluster with a dppm ligand bridging one of the Os–Os edges. Compound 2 consists of a closed triangular cluster of osmium atoms with a bridging SPh, and a bridging hydride ligand on the same Os–Os edge, and a dppm ligand bridging one of the remaining Os–Os edges

Synthesis and Reactivity of N,N,N’,N’-Tetramethyldiaminomethane (TMDM) Complexes of Tricarbonylrhenium(I). X-Ray Molecular Structures of [ReBr(CO)₃(TMDM)] and [{Re(bipy)(CO)₃}₂(μ-OH)][SbF₆].

N,N,N′,N′-Tetramethyldiaminomethane (TMDM) is known to act as a source of Me₂NCH in carbonyl substitution reactions, but the reaction of TMDM with the neutral halogenopentacarbonylrhenium(I) compounds gave unexpectedly fac-[ReX(CO)₃(TMDM)] (X=Cl, Br or I), in which the intact TMDM ligand acts in a chelating fashion. The complexes are stable both in the solid-state and in solution, but rapidly decompose on dehalogenation, yielding Re metal. Under anaerobic conditions, the reaction of TMDM with [Re(CO)₃(bipy)]⁺also leads to decomposition. In the presence of oxygen the system is stable. Three Re(bipy) containing species were identified in the reaction mixture: [{Re(CO)₃(bipy)}₂(μ-OH)][SbF₆] (1), which was characterised by X-ray crystallography, [{Re(CO)₃(bipy)}₂(μOH)₂][SbF₆]₂(2) and [Re(OH)(CO)₃(bipy)] (3). Graphical Abstract Reaction of neutral [ReX(CO)₅] (X=Cl, Br or I) with N,N,N′,N′-tetramethyldiaminomethane ((TMDM)) gave unexpectedly fac-[ReX(CO)₃(TMDM)] (X=Cl, Br or I), in which the intact TMDM ligand acts in a chelating fashion. Reaction of TMDM with [Re(CO)₃(bipy)]⁺ under aerobic conditions yields three complexes: [{Re(CO)₃(bipy)}₂(μ-OH)][SbF₆] (1), which was characterised by X-ray crystallography, [{Re(CO)₃(bipy)}₂(μOH₂)][SbF₆]₂(2) and [Re(OH)(CO)₃(bipy)] (3)

Trimethylplatinum(IV) complexes of dithiocarbamato ligands: an experimental NMR study on the barrier to C-N bond rotation.

The trimethylplatinum(IV) complexes of a number of dithiocarbamato ligands have been prepared. The complexes are dimeric in the solid-state and in solution, with the ligands acting in both a bridging and chelating fashion. Restricted rotation about the ligand C-N bonds in solution leads to the formation of four rotomers. The kinetics of the restricted rotation were measured by a variety of dynamic NMR techniques in the slow and intermediate exchange regimes. Two distinct processes are observed, namely the independent rotation about each C-N bond and correlated rotation about both C-N bonds. The free energies of activation, which are strongly dependent on the nature of the ligand substituents, are in the range 65 – 88 kJ mol-1 at 298 K. The origins of the barrier to rotation and the effects of the N substituents are discussed. The X-ray structures of fac-[PtMe3(Me2NCS2)]2 (2) and fac-[PtMe3(Ph(H)NCS2)]2 , (6) are reported

A detailed NMR study of the solution stereodynamics in tricarbonylrhenium(I) halide complexes of the non-racemic chiral ligand 2,6-bis[(4R,5R)-4,5-dimethyl-1,3-dioxolan-2-yl]pyridine (L¹) and the molecular structure of fac-[ReBr(CO)₃(L¹)]

1 Tricarbonylrhenium(I) halide complexes of the non-racemic chiral ligand 2,6-bis[(4R, 5R)-dimethyl-1,3-dioxan-2-yl]pyridine (L¹), namely fac-[ReX(CO)₃(L¹)] (X = Cl, Br or I), have been prepared. In these complexes the ligand is bound in a bidentate fashion, with the N atom of the pyridine ring and an O atom of one of the acetal rings co-ordinated to the octahedral metal centre. The bidentate mode is confirmed by the X-ray structure of fac-[ReBr(CO)₃(L¹)]. There are four possible diastereoisomers, depending on the configuration at the metal centre and at the acetal-carbon atom of the co-ordinated ring; the X-ray structure of fac-[ReBr(CO)₃(L¹)] shows that the SR diastereoisomer is present in the solid state. In solution, three of the four possible diastereoisomers are observed, namely SR, RR and RS; their relative populations are in the order SR > RR > SS. Above ambient temperature the complexes are stereochemically non-rigid. The fluxional kinetics have been measured by a combination of standard band shape analysis and selective inversion experiments. Two distinct processes are present: an acetal ring flip and exchange of the pendant and co-ordinated acetal rings. The latter process occurs via two independent mechanisms, namely tick-tock and rotation pathways. The activation energies for the stereodynamics are in the ranges 72 – 73 kJ mol⁻¹ (tick-tock), 77 – 78 kJ mol⁻¹ (acetal ring flip) and 83 – 90 kJ mol⁻¹ (rotation) at 298 K

Reactions of ( q6-arene) (q6-[2.2] paracyclophane) ruthenium( 11) Complexes with Nucleophiles

Single addition of the nucleophiles X-= H-, CN-or OH-t o (q6-arene) (q6-[2.2]paracyclophane)-ruthenium(r1) tetrafluoroborate (arene = benzene, p-cymene, 1,4-diisopropylbenzene or hexamethylbenzene) and the osmium(1i) q6-C6H6 analogue produces the (q5-cyclohexadienyl) (q6-[2.2] paracyclophane)metal(it) complexes as the sole products. These compounds have been identified by l H NMR and by infrared spectroscopy. The expected isotope shift is observed when Na[BD,] is used in place of Na [BH,]. The steric factors influencing the site of nucleophilic attack are discussed and nucleophilic addition to [ R~( q~-C ,~t i~~) , ] [BF,], is also examined. Both single and double nucleophilic addition to co-ordinated arenes is of significant interest as a synthetic route to arene functionalisation and a single nucleophilic attack is a key initial step in the recently reported synthesis of ( f )-dihydroxyserrulatic acid.' While bis(arene)ruthenium complexes are expected ' to be around thirty times less electrophilic than their iron analogues they display a number of advantages which make them the more attractive alternative in this type of work. These advantages include (a) the ready availability, uiu the Bennett and Rybinskaya 5.6 syntheses, of unsymmetrical complexes and (6) the elimination of interfering electrontransfer reactions 7-9 which can occur on the addition of carbondonor nucleophiles and result in the formation and often rapid decomposition of unstable nineteen-and twenty-electron species. Use of the highly sterically hindered [2.2]paracyclophane ligand has recently been shown to direct nucleophilic attack onto less-hindered arenes co-ordinated to the same metal centre" to produce q4-diene complexes such as [Ru(q6-cyclohexa-1,4-diene). In addition, protonation of an q4-C2.2)paracyclophane compound gives a co-ordinated q '-cyclophane with the added hydrogen atom in the endo position." That reaction is believed to involve the initial formation of a metal hydride foliowed by proton transfer to the carbocyclic ring. We now report the use of the [2.2]paracyclophane ligand to direct singk nucleophilic attack onto a number of q6-arenes and examine the question of exo or endo addition by a study of the effects of deuterium isotopic substitution on solid-state infrared and solution 'H NMR spectra. A preliminary report ofpart of this work has been published. ' ' c 1 gH 1 6)(q4-C6Me6H2)](C6Me6H2 = 1,2,3,4,5,6-hexamethyI- spaced doublet resonance ('JHH = 13.5 Hz) is observed at 6 2.06 and is assigned to He,, Results and Discussio

Reactions of Rhenium and Manganese Carbonyl Complexes with 1,8-bis(diphenylphosphino)naphthalene: Ligand Chelation, C–H and C–P bond-cleavage Reactions

Reaction of [Re2(CO)8(MeCN)2] with 1,8-bis(diphenylphosphino)naphthalene (dppn) afforded three mono-rhenium complexes fac-[Re(CO)3(κ1:η1-PPh2C10H6)(PPh2H)] (1), fac-[Re(CO)3{κ1:κ1:η1-(O)PPh2C10H6(O)PPh(C6H4)}] (2) and fac-[ReCl(CO)3(κ2-PPh2C10H6PPh2)] (3). Compounds 1–3 are formed by Re–Re bond cleavage and P–C and C–H bond activation of the dppn ligand. Each of these three complexes have three CO groups arranged in facial fashion. Compound 1 contains a chelating cyclometalated diphenylnaphthylphosphine ligand and a terminally coordinated PPh2H ligand. Compound 2 consists of an orthometalated dppn-dioxide ligand coordinated in a κ1:κ1:η1-fashion via both the oxygen atoms and ortho-carbon atom of one of the phenyl rings. Compound 3 consists of an unchanged chelating dppn ligand and a terminal Cl ligand. Treatment of [Mn2(CO)8(MeCN)2] with a slight excess of dppn in refluxing toluene at 72 °C, gave the previously reported [Mn2(CO)8(μ-PPh2)2] (4), formed by cleavage of C–P bonds, and the new compound fac-[MnCl(CO)3(κ2-PPh2C10H6PPh2)] (5), which has an unaltered chelating dppn and a terminal Cl ligand. In sharp contrast, reaction of [Mn2(CO)8(MeCN)2] with slight excess of dppn at room temperature yielded the dimanganese [Mn2(CO)9{κ1-PPh2(C10H7)}] (6) in which the diphenylnaphthylphosphine ligand, formed by facile cleavage of one of the P–C bonds, is axially coordinated to one Mn atom. Compound 6 was also obtained from the reaction of [Mn2(CO)9(MeCN)] with dppn at room temperature. The XRD structures of complexes 1–3, 5, 6 are reported