Linkage isomerism of organoplatinum(II) compounds coordinated by two 1,3‐di­methyl­barbiturate anions

In two linkage isomers, bis[1,3‐di­methyl‐2,4,6(1H,3H,5H)‐pyrimidine­trionato]‐C⁵,O⁴‐(ethyl­enedi­amine‐N,N′)platinum(II), [Pt(C₆H₇N₂O₃)₂(C₂H₈N₂)], (I), and bis[1,3‐di­methyl‐2,4,6(1H,3H,5H)‐py­rim­idine­tri­on­ato‐C⁵](ethyl­enediamine‐N,N′)­plati­num(II) di­hyd­rate, [Pt(C₆H₇N₂O₃)₂(C₂H₈N₂)]·2H₂O, (II), crystal­lized from the same aqueous solution containing [Pt(en)(OH)₂] and 1,3‐di­methyl­barbituric acid (Hdmbarb) in a 1:2 molar ratio, a pair of monodentate dmbarb^? anions coordinate to the Pt atom at tetrahedral C atoms for (II), while one dmbarb^? anion coordinates at the carbon and the other at a deprotonated enol oxy­gen for (I). The Pt—C distances in (I) and (II) are comparable: 2.112 (4) Å for (I), and 2.114 (4) and 2.117 (4) Å for (II).     

[N,N′‐Bis­(salicyl­idene)‐2,2‐di­methyl‐1,3‐propane­diaminato]­nickel(II) and [N,N′‐bis­(salicyl­idene)‐2,2‐di­methyl‐1,3‐propane­diaminato]copper(II)

In the title compounds, {2,2′‐[2,2‐di­methyl‐1,3‐propane­diyl­bis­(nitrilo­methyl­idyne)]­diphenolato‐κ⁴N,N′,O,O′}nickel(II), [Ni(C₁₉H₂₀N₂O₂)], and {2,2′‐[2,2‐di­methyl‐1,3‐propane­diyl­bis­(nitrilo­methyl­idyne)]­diphenolato‐κ⁴N,N′,O,O′}copper(II), [Cu(C₁₉H₂₀N₂O₂)], the Ni^II and Cu^II atoms are coordinated by two iminic N and two phenolic O atoms of the N,N′‐bis­(salicyl­idene)‐2,2‐di­methyl‐1,3‐propane­diaminate (SALPD^2?, C₁₇H₁₆N₂O₂^2?) ligand. The geometry of the coordination sphere is planar in the case of the Ni^II complex and distorted towards tetrahedral for the Cu^II complex. Both complexes have a cis configuration imposed by the chelate ligand. The dihedral angles between the N/Ni/O and N/Cu/O coordination planes are 17.20 (6) and 35.13 (7)°, respectively.     

trans‐Bis­[1‐methyl‐3‐(p‐nitro­phenyl)­triazenido 1‐oxide‐κ2N3,O]­di­pyridine­nickel(II)

In the centrosymmetric title complex, [Ni(C₇H₇N₄O₃)₂(C₅H₅N)₂], the coordination geometry about the Ni²⁺ ion is octahedral, with two deprotonated 1‐methyl‐3‐(p‐nitro­phenyl)­triazenide 1‐oxide ions, viz. [O₂N­C₆H₄­NNN(O)­CH₃]^?, acting as bidentate ligands (four‐electron donors). Two neutral pyridine (py) mol­ecules complete the coordination sphere in positions trans to each other. The triazenide 1‐oxide ligand is almost planar, the largest interplanar angle of 8.80 (12)° being between the phenyl ring of the p‐nitro­phenyl group and the plane defined by the N₃O moiety. The Ni—N_triazenide, Ni—O and Ni—N_py distances are 2.0794 (16), 2.0427 (13) and 2.1652 (18) Å, respectively.     

catena‐Poly­[[trans‐bis­(ethane‐1,2‐di­amine‐κ2N,N′)copper(II)]‐μ‐di­thion­ato‐κ2O:O′] and trans‐di­aqua­bis­(propane‐1,3‐di­amine‐κ2N,N′)copper(II) di­thionate

In title an­hydro­us catena‐poly­[[trans‐bis­(ethane‐1,2‐di­amine‐κ²N,N′)copper(II)]‐μ‐di­thionato‐κ²O:O′], [Cu(S₂O₆)(C₂H₈N₂)₂]_n or [{H₂N(CH₂)₂NH₂}₂Cu(O·O₂SSO₂·O)]_∞, successive Cu atoms are bridged by a single doubly charged di­thionate group, forming a one‐dimensional polymer with inversion centres at the metal atoms and the mid‐point of the S—S bond [Cu—O = 2.5744 (15) Å]. In title (hydrated) trans‐di­aqua­bis­(propane‐1,3‐di­amine‐κ²N,N′)copper(II) di­thionate, [Cu(C₃H₁₀N₂)₂(H₂O)₂](S₂O₆) or [{H₂N(CH₂)₃NH₂}₂Cu(OH₂)₂](S₂O₆), both ions have imposed 2/m symmetry. The `axial' anion components are displaced by a pair of water ligands [Cu—O = 2.439 (3) Å], the shorter Cu—O distance being compensated by the lengthened Cu—N distance [2.0443 (18), cf. 2.0100 (13) and 2.0122 (16) Å].     

Layered zincoarsenate templated by N,N,N′,N′‐tetra­methyl­ethyl­ene‐di­amine mol­ecules

The title compound, N,N,N′,N′‐tetra­methyl­ethyl­enedi­ammon­ium di­aqua­(arsenate)­(hydrogen arsenate)­dizinc(II), (C₆H₁₈N₂)_0.5[Zn₂(AsO₄)(HAsO₄)(H₂O)₂], is a new zincoarsenate obtained by hydro­thermal synthesis. The structure consists of infinite two‐dimensional anionic layers alternating with planes containing centrosymmetric organic diprotonated template N,N,N′,N′‐tetra­methyl­ethyl­enedi­ammonium cations, [H₃N­C₆H₁₂NH₃]²⁺. The latter are interconnected to the framework through hydrogen bonds.     

Linear chains in polymeric di­cyclo­hexyl­ammonium tri­butyl­(4‐oxo‐4H‐pyran‐2,6‐di­carboxyl­ato)­stannate and methyl­phenyl­ammonium tri­butyl(pyridine‐2,6‐di­carboxyl­ato)­stannate containing trigonal bipyramidal tin

catena‐Poly­[di­cyclo­hexyl­ammonium [tri­butyl­tin‐μ‐(4‐oxo‐4H‐pyran‐2,6‐di­carboxyl­ato‐O²:O⁶)]], (C₁₂­H₂₄N)­[Sn(C₇­H₂­O₆)(C₄H₉)₃], consists of 4‐oxo‐4H‐pyran‐2,6‐di­carboxyl­ato groups that axially link adjacent tri­butyl­tin units into a linear polyanionic chain. The ammonium counter‐ions surround the chain, and each cation forms a pair of hydrogen bonds to the double‐bond carbonyl O atoms of the same dianionic group. The chain propagates in a zigzag manner along the c axis of the monoclinic cell. In catena‐poly­[methyl­(phenyl)­ammonium [tri­butyl­tin‐μ‐(pyridine‐2,6‐di­carboxyl­ato‐O²:O⁶)]], (C₇H₁₀N)­[Sn(C₇H₃NO₄)­(C₄H₉)₃], the pyridine‐2,6‐di­carboxyl­ato groups also link the tri­butyl­tin groups into a chain, but the hydrogen‐bonded chain propagates linearly on the ac face of the monoclinic cell.     

A bis­(acetyl­acetonato)­uranium(IV) complex of the Schiff base N,N′‐bis(3‐hydroxy­salicyl­idene)‐2‐methyl‐1,2‐propane­di­amine

The title complex, bis­(acetyl­acetonato‐κ²O,O′)[N,N′‐bis(3‐hydroxy‐2‐oxidobenzaldimino)‐2‐methyl‐1,2‐propane­di­amine‐κ⁴N,O,O′,N′]­uranium(IV) tetra­hydro­furan solvate, [U(C₁₈H₁₈N₂O₄)(C₅H₇O₂)₂]·C₄H₈O, is a rare example of a uranium(IV) complex with a compartmental Schiff base. The U atom is located in the N₂O₂ inner site of the hexadentate N,N′‐bis(3‐hydroxy‐2‐oxidobenzaldimino)‐2‐methyl‐1,2‐pro­pane­di­amine group and is bound also to the two O atoms of both acetyl­acetonate moieties, which results in a dodecahedral coordination environment. Centrosymmetric dimers are formed through intermolecular hydrogen bonds that link the terminal uncoordinated hydroxy groups to one another and to the O atoms of the acetyl­acetonate ligands.     

20‐Di­cyano­methyl­ene‐5,8,11,14‐tetraoxa‐2,17‐di­thia­bi­cyclo­[16.4.1]­tricosa‐1(23),18,21‐triene and its mercury(II) dichloride complex

The structures of the title compound, C₂₀H₂₄N₂O₄S₂, and its mercury(II) dichloride complex, dichloro{20‐di­cyano­methyl­ene‐5,8,11,14‐tetraoxa‐2,17‐di­thia­bi­cyclo­[16.4.1]­tricosa‐1(23),18,­21‐tri­ene‐κ⁴O,κS¹⁷}mercury(II), [HgCl₂(C₂₀­H₂₄­N₂­O₄­S₂)], have been determined by X‐ray crystallographic analyses. The mercury(II) dichloride complex has two independent mol­ecules of [HgCl₂(C₂₀H₂₄N₂O₄S₂)] in the lattice. The mercury(II) ion has pentagonal bipyramidal coordination which involves one S atom, four O atoms and two Cl^? ions.     

A zigzag‐type one‐dimensional coordination polymer formed by (2,2‐di­methyl‐1,3‐propane­di­amine)­bis­(iso­nico­tin­ato)­platinum(II) and copper nitrate

The title compound, catena‐poly­[[[tri­aqua‐2κ³O‐(2,2‐dimethyl‐1,3‐propane­di­am­ine)‐1κ²N,N′‐μ‐isonicotinato‐1:2κ²N:O‐copper(II)­plati­num(II)]‐μ‐isonicotinato‐2:1′κ²O:N] dinitrate], {[CuPt(C₆H₄NO₂)₂(C₅H₁₄N₂)(H₂O)₃](NO₃)₂}_n, obtain­ed from equimolar (dmpda)Pt^II(isonic)₂ (where dmpda is 2,2‐di­methyl‐1,3‐propane­di­amine and isonic is isonicotinate) and copper(II) nitrate, has been found to be a one‐dimensional coordination polymer of the zigzag‐type.     

A 1:1 adduct between di­methyl­tin dibromide and N‐methyl­pyrrolidinone (NMP)

The title compound, di­bromo­di­methyl(N‐methyl­pyrrolidin‐2‐one‐O)­tin(IV), [SnBr₂(CH₃)₂(C₅H₉NO)], exhibits pentacoordination of the Sn atom, with long and short Sn—Br bonds [2.6737 (4) and 2.5256 (4) Å, respectively]. The distorted trigonal–bipyramidal coordination polyhedron has two methyl groups and one Br atom in the equatorial plane, the second Br atom and the N‐methyl­pyrrolidinone (NMP) ligand occupying the apical positions.     

Copper(II) and zinc(II) complexes of pyridine‐2,6‐di­carboxyl­ic acid

The title compounds, bis­(pyridine‐2,6‐di­carboxyl­ato‐N,O,O′)copper(II) monohydrate, [Cu(C₇H₄NO₄)₂]·H₂O, andbis(pyridine‐2,6‐dicarboxylato‐N,O,O′)zinc(II) trihydrate, [Zn(C₇H₄NO₄)₂]·3H₂O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl‐N atoms from the two terdentate ligand mol­ecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand mol­ecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand mol­ecules. Both crystal structures are stabilized by O—H?O intermolecular hydrogen bonds between the complex and the water mol­ecules.     

Bis­(acetato‐κ2O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ2N,N′)mercury(II) in two differently hydrated crystal forms

Two differently hydrated crystal forms of the title compound, viz. bis­(acetato‐κ²O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ²N,N′)­mercury(II), [Hg(C₂H₃O₂)₂(C₁₄H₁₂N₂)] or [HgAc₂(dmph)] [dmph is 2,3‐di­methyl‐1,10‐phenantroline (neocuproine) and Ac is acetate], (I), and tris­[bis­(acetato‐κ²O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ²N,N′)­mercury(II)] hexadecahydrate, [Hg(C₂H₃O₂)₂(C₁₄H₁₂N₂)]₃·16H₂O or [HgAc₂(dmph)]₃·16H₂O, (II), are presented. Both structures are composed of very simple monomeric units, which act as the building blocks of complex packing schemes stabilized by a diversity of π–π and hydrogen‐bonding interactions.     

Bis(μ‐ethyl pyridine‐2,6‐di­carboxyl­ato)­bis­[di­aqua­chloro­cadmium(II)] dihydrate

The reaction of cadmium chloride with pyridine‐2,6‐di­carboxylic acid (PDA) and 98% H₂SO₄ in ethanol led to the formation of the title compound, bis­[μ‐6‐(ethoxy­carbonyl)­pyridine‐2‐carboxyl­ato]‐1:2κ⁴O⁶,N,O²:O²;1:2κ⁴O²:O²,N,O⁶‐bis­[di­aqua­chloro­cadmium(II)] dihydrate, [Cd₂(C₉H₈NO₄)₂Cl₂(H₂O)₄]·2H₂O. PDA is esterified to monoethyl ­pyridine‐2,6‐di­carboxyl­ate (MEPD) by the catalysis of H₂SO₄ during the reaction. The dinuclear Cd^II complex lies about an inversion centre and the unique Cd atom has a pentagonal–bipyramidal geometry. The two Cd atoms are bridged by two carboxyl­ate O atoms, forming a planar Cd₂O₂ unit. Stair‐like chains are formed via O—H⋯Cl hydrogen bonds and these are further arranged into two‐dimensional layers via hydrogen bonds involving solvate water mol­ecules.     

Transition metal complexes with pyrazole‐derived ligands. XI. [Zn(μ‐L)(HL)(OAc)]2 (HL is 4‐acetyl‐3‐amino‐5‐methyl­pyrazole)

The title compound, bis(μ‐4‐acetyl‐3‐amino‐5‐methyl­pyrazol­ato‐N¹:N²)­bis­[(acetato‐O)­(4‐acetyl‐3‐amino‐5‐methyl­pyraz­ole‐N²)­zinc(II)], [Zn₂(C₆H₈N₃O)₂(C₂H₃O₂)₂(C₆H₉N₃O)₂], ex‐ists as a centrosymmetric binuclear mol­ecule with two tetrahedrally coordinated Zn atoms bridged by two pyrazolate anions. The geometry of the terminal and bridging pyrazole ligands are slightly different as a consequence of their differing modes of coordination.     

2(S)‐Amino‐3‐[1H‐imidazol‐4(5)‐yl]­propyl cyclo­hexylmethyl ether di­hydro­chloride and 2(S)‐amino‐3‐[1H‐imidazol‐4(5)‐yl]­propyl 4‐bromo­benzyl ether di­hydro­chloride

(Cyclo­hexyl­methyl­oxy­methyl)(1H‐imidazol‐4‐io­methyl)‐(S)‐ammonium dichloride, C₁₃H₂₅N₃O⁺·2Cl^?, and (4‐bromo­benzyl)(1H‐imidazol‐4‐io­methyl)‐(S)‐ammonium dichloride, C₁₃H₁₈BrN₃O⁺·2Cl^?, are model compounds with different biological activities for evaluation of the hist­amine H3‐receptor activation mechanism. Both title compounds occur in almost similar extended conformations.     

Bis(acesulfamato‐κ2N3,O4)bis­(2‐amino­pyrimidine‐κN1)copper(II)

In the crystal structure of the title compound, bis­(2‐amino­pyrimidine‐κN¹)bis­[6‐meth­yl‐1,2,3‐oxathia­zin‐4(3H)‐one 2,2‐dioxide(1−)‐κ²N³,O⁴]copper(II), [Cu(C₄H₄NO₄S)₂(C₄H₅N₃)₂], the first mixed‐ligand complex of acesulfame, the Cu^II centre resides on a centre of symmetry and has an octa­hedral geometry that is distorted both by the presence of four‐membered chelate rings and by the Jahn–Teller effect. The equatorial plane is formed by the N atoms of two amino­pyrimidine (ampym) ligands and by the weakly basic carbonyl O atoms of the acesulfamate ligands, while the more basic deprotonated N atoms of these ligands are in the elongated axial positions with a strong misdirected valence. The crystal is stabilized by pyrimidine ring stacking and by inter­molecular hydrogen bonding involving the NH₂ moiety of the ampym ligand and the carbon­yl O atom of the acesulfamate moiety.     

Bis(μ‐hexa­methyl­enetetr­amine)­bis(aqua­di­bromo­cadmium)­di­aqua­di­bromo­cadmium dihydrate

The title compound, poly­[[di­aqua­di­bromo­cadmium‐μ‐(1,3,5,7‐tetra­aza­tri­cyclo[3.3.1.1^3,7]decane‐N¹:N⁵)‐aqua­cad­mium‐di‐μ‐bromo‐aqua­cadmium‐μ‐(1,3,5,7‐tetra­aza­tri­cyclo[3.3.1.1^3,7]decane‐N¹:N⁵)‐di‐μ‐bromo] dihydrate], [Cd₃­Br₆­(C₆­H₁₂­N₄)₂­(H₂O)₄]·­2H₂O, is made up of two‐dimensional neutral rectangular coordination layers. Each rectangular subunit is enclosed by a pair of Cd₃(μ₂‐Br)₆(H₂O)₃ fragments and a pair of (μ₂‐hmt)Cd(H₂O)₂Br₂(μ₂‐hmt) fragments as sides (hmt is hexa­methyl­enetetr­amine). The unique Cd^II atom in the Cd₂Br₂ ring in the Cd₃(μ₂‐Br)₆(H₂O)₃ fragment is in a slightly distorted octahedral CdNOBr₄ geometry, surrounded by one hmt ligand [2.433 (5) Å], one aqua ligand [2.273 (4) Å] and four Br atoms [2.6409 (11)–3.0270 (14) Å]. The Cd^II atom in the (μ₂‐hmt)Cd(H₂O)₂Br₂(μ₂‐hmt) fragment lies on an inversion center and is in a highly distorted octahedral CdN₂O₂Br₂ geometry, surrounded by two trans‐related N atoms of two hmt ligands [2.479 (5) Å], two trans‐related aqua ligands [2.294 (4) Å] and two trans‐related Br atoms [2.6755 (12) Å]. Adjacent two‐dimensional coordination sheets are connected into a three‐dimensional network by hydrogen bonds involving lattice water mol­ecules, and the aqua, bromo and hmt ligands belonging to different layers.     

The mononuclear cobalt(II) complex CoII(DMBDIZ)2(NCS)2, where DMBDIZ is 2,6‐di­methyl­benzo[1,2‐d:4,5‐d′]­di­imidazole

In the title mononuclear cobalt complex, bis(2,6‐di­methyl‐1H,7H‐benzo­[1,2‐d:4,5‐d′]­di­imidazole‐κN³)­bis­(thio­cyanato‐κN)cobalt(II), [Co^II(NCS)₂(DMBDIZ)₂] or [Co(NCS)₂(C₁₀H₁₀N₄)₂], the cobalt(II) ion is coordinated to four N atoms, from two thio­cyanate anions and two DMBDIZ ligands, in a distorted tetrahedral geometry. In the DMBDIZ ligand, the two imine N atoms are positioned cis with respect to one another. The crystal packing of the complex is dominated by both hydrogen bonding, involving two N—H?N and two N—H?S interactions, and aromatic π–π stacking.     

Two isomeric di­deoxy­nucleosides

We have synthesized two isomeric di­deoxy­nucleosides. 4(S)‐(6‐Amino‐9H‐purin‐9‐yl)‐3‐methyl­ene‐2,3,4,5‐tetra­hydrofuran‐2(S)‐yl­methanol, C₁₁H₁₃N₅O₂, is an analogue of the anti‐HIV compound (S,S)‐isodi­deoxy­adenosine (isoDDA) with an exocyclic methyl­ene group and is found to be anti‐HIV inactive. The solid‐state comformation is very similar to that of isoDDA. 4(S)‐(6‐Amino‐3H‐purin‐3‐yl)‐3‐methyl­ene‐2,3,4,5‐tetra­hydro­furan‐2(S)‐ylmethanol, C₁₁H₁₃N₅O₂, has an isomeric arrangement of the carbohydrate and base moieties, as confirmed by the crystal structure analysis. The asymmetric unit contains two independent mol­ecules that differ in conformations at the sugar moiety.     

A donor–acceptor compound composed of a di­nuclear zinc(II) complex of a Robson macro­cycle with 8‐methyl­quino­line

A donor–acceptor compound, di­aqua‐1κO,2κO‐[μ‐11,23‐dimethyl‐3,7,15,19‐tetra­aza­tri­cyclo­[19.3.1.1^9,13]hexacosa‐1(25),2,7,9,11,13(26),14,19,21,23‐decaene‐25,­26‐diolato‐1κ⁴N³,N⁷,O²⁵,O²⁶:­2κ⁴N¹⁵,N¹⁹,O²⁵,O²⁶]­dizinc(II) diperchlorate bis(8‐methyl­quinoline) ethanol disolvate, [Zn₂(C₂₄H₂₆N₄O₂)(H₂O)₂](ClO₄)₂·2C₁₀H₉N·2C₂H₆O, obtained by the reaction of a dinuclear zinc(II) complex of a Robson macrocycle (acceptor) and 8‐methyl­quinoline (donor), lies about an inversion centre and the coordination about the unique Zn atom is a distorted square pyramid. The fifth coordination site is occupied by the water mol­ecule, Zn—O = 2.016 (2) Å, and the average macrocyclic Zn—O and Zn—N distances are 2.059 (6) and 2.059 (3) Å, respectively.