Two scandium–biuret complexes: [Sc(C2H5N3O2)(H2O)5]Cl3·H2O and [Sc(C2H5N3O2)4](NO3)3

The scandium(III) cations in the structures of pentaaqua(biuret‐κ²O,O′)scandium(III) trichloride monohydrate, [Sc(C₂H₅N₃O₂)(H₂O)₅]Cl₃·H₂O, (I), and tetrakis(biuret‐κ²O,O′)scandium(III) trinitrate, [Sc(C₂H₅N₃O₂)₄](NO₃)₃, (II), are found to adopt very different coordinations with the same biuret ligand. The roles of hydrogen bonding and the counter‐ion in the establishment of the structures are described. In (I), the Sc³⁺ cation adopts a fairly regular pentagonal bipyramidal coordination geometry arising from one O,O′‐bidentate biuret molecule and five water molecules. A dense network of N—H...Cl, O—H...O and O—H...Cl hydrogen bonds help to establish the packing, resulting in dimeric associations of two cations and two water molecules. In (II), the Sc³⁺ cation (site symmetry 2) adopts a slightly squashed square‐antiprismatic geometry arising from four O,O′‐bidentate biuret molecules. A network of N—H...O hydrogen bonds help to establish the packing, which features [010] chains of cations. One of the nitrate ions is disordered about an inversion centre. Both structures form three‐dimensional hydrogen‐bond networks.     

Crystal Structure of Tetrakis (phenacetin) Dihydrogentetraiodide Dihydrate {[H5C2OC6H4N (H)C(CH3)O]4·H2I4·2H2O}

(Phenacetin)₄·₂I₄·2H₂O is triclinic, a = 13.641 (7), b = 12.807 (6), c = 7.201 (3) Å, α = 99.8 (4), b? = 86.5 (4), γ = 104.0 (5)°, P1 , Z = 1. The ordered crystal structure has been refined to R_F = 0.050, using 4173 independent reflections measured on a four-circle diffractometer with MoKa (graphite monochromator) radiation. The crystals are composed of alternating positively and negatively charged slices; each positive slice contains a double layer of stacks of hemi-protonated phenacetin molecules which are H-bonded through their carbonyl groups (d(O - - - O) = 2.432 (4) Å) while each negative slice contains a single layer of I^2?₄-ions linked in chains along [100] through H-bonds to pairs of water molecules. The axes of the phenacetin stacks are parallel to the planes of the (I^2?₄·2H₂O)-layers. The I^2?₄-ion is centro-symmetric and can be approximately represented as I^?- - - I–I- - - I^? (d(I^? - - - I) = 3.404 (1) Å; d(I–I) = 2.774 (1) Å). The compound is a pseudo-type A basic salt.     

Quervernetzung lamellarer Schichten mit Hilfe von (O–H…O)‐Wasserstoffbrücken: Strukturen von M⊕⊖N(SO2C6H4‐4‐COOH)2 (M⊕ = K⊕, Rb⊕, Cs⊕)

Structures of Ionic Di(arenesulfonyl)amides. 4. Cross‐Linking Lamellar Layers by O–H…O Hydrogen Bonds: Structures of M^⊕⊖N(SO₂C₆H₄‐4‐COOH)₂ (M^⊕ = K^⊕, Rb^⊕, Cs^⊕) Syntheses and low‐temperature X‐ray crystal structures are reported for M^IN(SO₂C₆H₄‐4‐COOH)₂, where M = K (monoclinic, space group P2₁/c, Z = 4, Z′ = 1), M = Rb (monoclinic, P2₁, Z = 4, Z′ = 2), or M = Cs (monoclinic, P2₁/c, Z = 4, Z′ = 1). The three compounds are examples of layered inorgano‐organic solids where the inorganic component is comprised of metal cations and N(SO₂)₂ groups and the outer regions are formed by the 4‐carboxy substituted phenyl rings of the folded anions. In the two‐dimensional coordination networks, K^⊕ and Cs^⊕ adopt irregular and chemically distinct [MN₁O₇] octacoordinations, whereas the independent Rb^⊕ cations attain irregular nonacoordinations of type [RbN₂O₇] or [RbO₉] respectively. The crystal packings of the compounds are governed by self‐assembly of parallel layers through exhaustive hydrogen bonding between carboxylic acid groups, resulting in a dense array of cyclic (COOH)₂ motifs within the interlamellar regions.     

Photocatalytic C(sp3) radical generation via C–H,C–C,and C–X bond cleavage

C(sp³) radicals (R˙) are of broad research interest and synthetic utility. This review collects some of the most recent advancements in photocatalytic R˙ generation and highlights representative examples in this field. Based on the key bond cleavages that generate R˙, these contributions are divided into C–H, C–C, and C–X bond cleavages. A general mechanistic scenario and key R˙-forming steps are presented and discussed in each section.

C(sp³) radicals (R˙) are of broad research interest and synthetic utility.     

Syntheses and structures of two chiral zincophosphite compounds: [Zn(C8H8N2)(HPO3)] and (C6H13N2)[Zn3(C6H12N2)(HPO3)3(H2PO3)

Employing achiral organic amines (2-methylbenzimidazole and 1,4-diazabicyclo[2.2.2]octane) as the structure-directing agent and ligand, two chiral zincophosphites, [Zn(C(8)H(8)N(2))(HPO(3))] 1 and (C(6)H(13)N(2))[Zn(3)(C(6)H(12)N(2))(HPO(3))(3)(H(2)PO(3))] 2, have been hydro(solvo)-thermally synthesized, crystallizing in the chiral space group P2(1)2(1)2(1). Single-crystal structural analysis reveals that compound 1 consists of alternating ZnO(3)N and HPO(3) units exhibiting a neutral one-dimensional chiral chain. Interestingly, the organic ligands interact with the inorganic chain via hydrogen-bonds in hydrogen-bonded helix fashion. Compound 2, a three-dimensional chiral open framework with 16-MR channels, is formed by the distorted {Zn(3)P(4)} secondary building unit (SBU). The organic amine molecules play dual roles as both ligands and countercations.     

Ein Praseodymsalz der Dichloressigsäure: [Pr(HCl2C—COO)3(H2O)3]2(HCl2C—COOH)(H2O)2

A Praseodymium Salt of Dichloroacetic Acid: [Pr(HCl₂C—COO)₃(H₂O)₃]₂(HCl₂C—COOH)(H₂O)₂ The new dichloroacetate of praseodymium, [Pr(HCl₂C—COO)₃(H₂O)₃]₂(HCl₂C—COOH)(H₂O)₂, crystallizes from the solution of ?Pr₆O₁₁”? in dichloroacetic acid. The crystal structure (monoclinic, P2₁/n, Z = 4, a = 1598.4(2), b = 1600.8(2), c = 1650.8(2) pm, β = 105.57(1)°) contains dimeric building units of the composition [Pr₂(HCl₂C—COO)₆(H₂O)₆] which are connected to chains. An additional dichloroacetic acid molecule and two crystal water molecules are included between these chains.