Metalation Triggers Single Crystalline Order in a Porous Solid

We report the dramatic triggering of structural order in a Zr(IV)-based metal-organic framework (MOF) through docking of HgCl₂ guests. Although as-made crystals were unsuitable for single crystal X-ray diffraction (SCXRD), with diffraction limited to low angles well below atomic resolution due to intrinsic structural disorder, permeation of HgCl₂ not only leaves the crystals intact but also resulted in fully resolved backbone as well as thioether side groups. The crystal structure revealed elaborate HgCl₂-thioether aggregates nested within the host octahedra to form a hierarchical, multifunctional net. The chelating thioether groups also promote Hg(II) removal from water, while the trapped Hg(II) can be easily extricated by 2-mercaptoethanol to reactivate the MOF sorbent.

Cyclometalated (boroxinato)gold(iii) complexes from arrested transmetalation

Luminescent metallaboroxines of gold(iii) form in self-assembly reactions from trifluoroacetato precursors and alkyl or arylboronic acids.

In situ production of silver nanoparticles on an aldehyde-equipped conjugated porous polymer and subsequent heterogeneous reduction of aromatic nitro groups at room temperature

Silver lining on porous polymer – all from heating Tollen's reagent and a polymer host deriving its versatile functions from pendant aldehyde groups and rigid thioether joints.

Functional shakeup of metal–organic frameworks: the rise of the sidekick

The ever more versatile side groups, from labile weak donors to strong-binding thiol and dendritic functions, sulfur-enabled framework chemistry heralds a rising trend in the design of solid-state materials.

Suzuki-Miyaura coupling of arylboronic acids to gold(iii)

Cyclometalated gold(iii) aryls are prepared through palladium catalysis. Mono- and diarylation are demonstrated. A wide range of functional groups is tolerated.

Gold(iii) is prominent in catalysis, but its organometallic chemistry continues to be restricted by synthesis. Metal–carbon bond formation often relies on organometallic complexes of electropositive elements, including lithium and magnesium. The redox potential of gold(iii) interferes with reactions of these classic reagents. Resort to toxic metals is common, including reagents based on mercury and thallium. We report that the palladium-catalyzed Suzuki–Miyaura coupling of arylboronic acids extends to cyclometalated gold(iii) chlorides. Both monoarylation and diarylation are achieved. We propose a mechanism where oxidative addition to palladium with rearrangement at gold(iii) fixes the stereochemistry of monoarylated intermediates. Singly arylated species form as thermodynamic isomers. These entities then go on to form diarylated complexes. Reactions proceed at room temperature, and the products are stable to air, moisture, and chromatography.

Synthesis, structure and magnetic properties of Nd3+ and Pr3+ 2D polymers with tetrafluoro-p-phthalate

Two lanthanide tetrafluoro-p-phthalate (L(2-)) complexes, Ln(L)(1.5)·DMF·H(2)O (Ln = Pr(3+) (1), Nd(3+) (2)), were synthesized using pyridine as a base. The compounds were found to be isostructural, and the structure of 1 has been determined by single crystal X-ray diffraction (monoclinic, space group C2, a = 22.194(2) Å, b = 11.4347(12) Å, c = 11.7160(12) Å, β = 94.703(2)°, V = 2963.3(5) Å(3), Z = 4). The crystal structure of 1 consists of dinuclear Pr(3+) units, which are connected by tetrafluoro-p-phthalate, forming separate 2D polymeric layers. The Ln(3+) ions in the dinuclear Ln(2) units are linked by two μ-O atoms and by two bridging O-C-O groups. The structure is porous with DMF and water molecules located between layers. Non-coordinated DMF molecules occupy about 27% of the unit cell volume. A systematic analysis of reported structures of Ln(III) polymers with p-phthalate and its derivatives shows that the ca. known 60 structures can be divided into six possible structural types depending on the presence of certain structural motifs. The magnetic properties of compounds 1 and 2 were studied. The dependence of χ(M)T on T (where χ(M) is magnetic susceptibility per dinuclear lanthanide unit) for 1 and 2 was simulated using two different models, based on: (i) the Hamiltonian Ĥ = ΔĴ(z)(2)+ μ(B)g(J)HĴ, which utilises an axial splitting parameter Δ and temperature-independent paramagnetism (tip) and (ii) crystal field splitting. It was found that both models gave satisfactory fits, indicating that the Ln-Ln exchange interactions are small and the symmetry of the coordination environment is the main factor influencing the magnetic properties of these compounds.

catena-Poly[[[tetra-kis-(4-methyl-pyridine-κN)copper(II)]-μ-sulfato-κO:O'] 4.393-hydrate]

The structure of the title compound, {[Cu(SO₄)(C₆H₇N)₄]·4.393H₂O}_n, consists of Cu²⁺ ions surrounded in a square-planar fashion by 4-methyl­pyridine ligands, forming two crystallographically independent Cu{H₃C(C₅H₄N)}₄ units that are both located on crystallographic inversion centers. The Cu(4-methyl­pyridine)₄ units are, in turn, connected with each other via bridging sulfate anions, leading to the formation of infinite [Cu{H₃C(C₅H₄N)}₄SO₄]_n zigzag chains along [001]. The completed coordination spheres of the Cu²⁺ ions are slightly distorted octa­hedral. The axial Cu—O bonds are elongated [average length = 2.42 (4) Å] compared to the equatorial Cu—N bonds [average length = 2.043 (2) Å]. The inter­stitial space between the chains is filled with uncoordinated water mol­ecules that consolidate the structure through O—H⋯O hydrogen bonding. One of the five crystallographically independent solvent water mol­ecules is partially occupied with an occupancy factor of 0.396 (4). Due to hydrogen bonding between symmetry-equivalent water mol­ecules across inversion centers, several of the water H atoms are disordered in 1:1 ratios over mutually exclusive positions. The crystal under investigation was found to be non-merohedrally twinned in a 0.789 (1):0.211 (1) ratio by a 180° rotation around the reciprocal b axis.

2,2'-[4,10-Bis(carb-oxy-meth-yl)-4,10-diaza-1,7-diazo-niacyclo-dodecane-1,7-di-yl]diacetate dihydrate

In the title compound, C₁₆H₂₈N₄O₈·2H₂O, the 12-membered macrocycle has twofold crystallographic symmetry and the asymmetric unit comprises one half-mol­ecule. The four carbox­yl/carboxyl­ate groups reside on the same side of the macrocycle. The mol­ecule is a double zwitterion with two of the carb­oxy­lic acid H atoms transferred to the two N atoms on the opposite sides of the macrocycle, resulting in both N atoms having positive charges and leaving the two resulting carboxyl­ate groups with negative charges. The two remaining carb­oxy­lic acid groups and the carboxyl­ate groups form O—H⋯O hydrogen bonds with the crystal water mol­ecules. The H atoms bound to the N atoms within the macrocyle are engaged in two equivalent hydrogen bonds with the adjacent N atoms.

New alkylzinc complexes with bulky tris(triazolyl)borate ligands: surprising water stability and reactivity

Bulky alkylzinc complexes, (Ttz(tBu,Me))ZnMe and (Ttz(tBu,Me))ZnEt, show remarkable stability towards water and both complexes crystallize with one molecule of adventitious water hydrogen bonded to two triazole rings; in contrast the less bulky complex, (Ttz(Ph,Me))ZnEt, reacts with water to yield (Ttz(Ph,Me))(2)Zn.

Tetra-kis[(3-hydroxy-prop-yl)dimethyl-ammonium] tetra-μ-acetato-κO:O'-bis-[chloridocuprate(II)](Cu-Cu) dichloride

The title compound (C₅H₁₄NO)₄[Cu₂(CH₃COO)₄Cl₂]Cl₂, consists of a pair of Cu^II ions bridged by four acetate groups, resulting in a Cu₂(CH₃COO)₄ unit, four (3-hydroxy­prop­yl)dimethyl­ammonium cations (two crystallographically independent pairs) and two chloride anions. The Cu atoms at both termini are bonded to chloride anions. The latter are hydrogen bonded to one of the two pairs of crystallographically independent (3-hydroxy­prop­yl)dimethyl­ammonium cations. The Cu₂(CH₃COO)₄ unit is located on a crystallographic inversion center, and the geometry around each metal center is close to octa­hedral. The Cl—Cu—Cu angles are nearly linear [177.48 (2)°] and the Cu—O bond lengths are in the range 1.9712 (18)–1.9809 (19) Å. The Cu⋯Cu separation between the two acetate-bridged Cu^II centers is 2.6793 (8) Å. The packing of the crystal structure is dominated by N—H⋯Cl hydrogen bonding between the ammonium groups and the chloride anions, as well as by O—H⋯O and O—H⋯Cl hydrogen bonds. One of the 3-hydroxypropyldimethylammonium cations shows orientational disorder with an occupancy ratio of 0.812 (4): 0.188 (4).

[Bis-(diphenyl-phosphino)methane-κP,P']dichloridopalladium(II)

The title complex, [PdCl₂(C₂₅H₂₂P₂)], is a slightly distorted square-planar bis­(diphenyl­phosphino)methane cis-complex of PdCl₂. The structure of a polymorph of the title compound has been described earlier, but the arrangement of the mol­ecules observed in the current structure is distinctively different from that previously reported [Steffen & Palenik (1976 ▶). Inorg. Chem.15, 2432–2439]. The earlier report describes a structure with individual well separated mol­ecules crystallizing in space group P2₁/n. The polymorph described here, which is isostructrural to its Pt analogue [Babai et al. (2006 ▶). Z. Anorg. Allg. Chem.632, 639–644], crystallizes in C2/c with chains of C2-symmetric mol­ecules stretching parallel to the b axis. The Pd atoms and the bis­phosphino­methane units are located on two different positions created by a non-crystallographic mirror operation with an occupancy of 0.6677 (11) for the major (PCH₂P)Pd moiety. The positions of the Cl atoms of the minor moiety do coincide perfectly with those of the next mol­ecule along the chain parallel to b, and they are thus not included in the disorder. The phenyl rings also do not take part in the disorder and are common to both the major and minor moieties of the (PCH₂P)PdCl₂ units. Assuming no defects, mol­ecules in each chain will thus have to be oriented the same way and the effect of the disorder of the (PCH₂P)Pd unit is thus a reversal in direction of the chains parallel to b. The presence of light streaks of intensity between actual Bragg peaks indicates that a somehow ordered arrangement not resolved in the Bragg diffraction data may be present (i.e. an incommensurate superstructure) rather than a random or domain arrangement of the chains.