Carlos Miravitlles

Bimetallic compounds of trans-cyclohexane-1,2-diamine-NNN′N′-tetra-acetate (cdta). Part 3. Structural and magnetic characterization of the dinuclear [M(OH2)5][M′(cdta)]·H2O (M,M′= Ni,Ni; Mn,Ni; Mn,Cu; Co,Ni; or Co,Cu) and the tetranuclear [M(OH2)4][M′(cdta)(OH2)]·4H2O (M,M′= Zn,Zn; Zn–Co; Co,Co; or Mn,Co) complexes

The crystal structures of the complexes [Co(OH2)5][Cu(cdta)]·H2O (5), [Zn(OH2)4][Zn(cdta)(OH2)]·4H2O (6), and [Zn0.7Co0.3(OH2)4][Zn0.3Co0.7(cdta)(OH2)]·4H2O (7)(cdta =trans-cyclohexane-1,2-diamine-NNN′N′-tetra-acetate) have been determined by X-ray methods. They crystallize in space groups Pbc21, P21/n, and P21/n respectively. The respective unit-cell constants are: a= 10.878(5), 9.702(2), 9.731(9)A; b= 11.757(5), 11.757(2), 11.783(2)A; c= 17.446(14), 20.980(5), 21.031(9)Aβ= 90,95.61(2), 95.40(6)°. The Z value is 4 for all three compounds. The structures were solved by direct methods and refined to final respective R values of 0.056, 0.098, and 0.041. The structure of (5) consists of dinuclear entities, constructed from cationic [Co(OH2)5]2+ and anionic [Cu(cdta)]2– molecules which are linked through a bridging carboxylate group from the cdta ligand. In (6) and (7), the species [M(2)(OH2)4]2+ and [M(1)(cdta)(OH2)]2–[M(1), M (2)= Zn,Co], sharing two oxygen atoms from different carboxylate groups, alternate in order to form tetranuclear entities. Magnetic properties in the range 1–100 K of compound (5) and those of the derivatives [Ni(OH2)5][Ni(cdta)]·H2O (1), [Mn(OH2)5][Ni(cdta)]·H2O (2), [Mn(OH2)5][Cu(cdta)·H2O(3)], [Co(OH2)5][Ni(cdta)]·H2O (4), [Co(OH2)4][Co(cdta)(OH2)]·4H2O (8), and [Mn(OH2)4][Co(cdta)(OH2)]·4H2O (9) are discussed by assuming a Heisenberg or lsing exchange coupling between the two metal ions with distinct Lande factors and local distortion parameters. All the compounds show antiferromagnetic behaviour at low temperatures, with exchange coupling parameters ranging from –0.8 [(5)] to –8.8 cm–1[(4)].

Closely related macrocyclic and acyclic tridentate, pyridine derivatives, containing sulphur, and their complexes. Crystal structures of {dichloro-3,10-dithia-16-azabicyclo[l0.3.1]hexadeca-1(16),12,14-triene}copper(II) and [2,6-bis(ethyithiomethyl)pyridine]dichlorocopper(II)

Four closely related, tridentate, pyridine derivatives, containing sulphur, three of them macrocyclic, 3,10-dithia-16-azabicyclo[10.3.1]hexadeca-1 (16),12,14-triene (L1), 3,8- dithia-14-azabicyclo-[8.3.1]tetradeca-1 (14),10,12-triene (L2), 3,7-dithia-13- azabicyclo[7.3.1]trideca-1 (13),9,11 -triene(L3), and one acyclic, 2,6-bis(ethylthiomethyl)pyridine (L4), have been prepared. All contain the same co-ordination elements (NS2) structurally placed in the same fashion, sulphur–methylene–pyridine–methylene–sulphur. Copper complexes of all the ligands and the palladium complex of L1 have also been prepared. The molecular structures of the complexes [CuL1Cl2] and [CuL4Cl2] are described. The latter is monoclinic, space group I2/c, with a= 14.669(6), b= 7.418(4), c= 29.412(8)A, β= 103.03(4)°, and Z= 8. The former is monoclinic, space group P2/a with a= 14.677(9), b= 7.555(1), c= 29.969(4)A, β= 101.00(2)°, and Z= 8. The different reactivity of the macrocycle ligand L1 with respect to that of L4 is discussed.

Perchlorophenyl-germanium compounds. Crystal and molecular structure of perchlorotriphenylgermane

Abstract The synthesis of the first pentachlorophenyl derivatives of organo-germanium compounds, perchlorotriphenylgermane ( 1 ), tris(pentachlorophenyl)germane( 2 ) and bromotris(pentachlorophenyl)germane ( 4 ), are reported; hydrolysis of 1 and 4 under neutral conditions gives tris(pentachlorophenyl)germanol ( 3 ). The structure of the germane 1 has been established by X-ray crystallography.

Co-ordination of the crown thioether 2,5,8-trithia[9]-o-benzenophane (L1). Synthesis and crystal structures of [CuL1(CI)] and [NiL12][BF4]2

The co-ordination abilities of 2,5,8-trithia[9]-o-benzenophane (L1) are compared with several S3-crown macrocycles by structural, spectral and electrochemical techniques. Ligand L1 shows intermediate behaviour relative to the well known ligands 1,4,7-trithiacyclononane and 1,5,9-trithiacyclododecane. The synthesis and characterization of CuII, CuI, NiII and CoII complexes with L1 are carried out. Crystal and molecular structures of two complexes are determined: [CuL1(Cl)], monoclinic, space group P21/a, a= 13.562(6), b= 8.046(1), c= 13.770(6)A, β= 109.96(2)°, Z= 4, R= 0.041 and R′= 0.045; [NiL21][BF4]2, monoclinic, space group P21/c, a= 9.430(2), b= 14.879(2), c= 11.451(2)A, β= 113.59(1)°, Z= 2, R= 0.058 and R′= 0.057.

An unusual cyclization reaction in the chemistry of perchloroorganic compounds of silicon and germanium. Synthesis and crystal structure of perchloro(2,2′-biphenylene)diphenyl-silane and -germane

Abstract The reactions of SiCl 4 and GeCl 4 (or Ph Cl ) 3 SiCl and (Ph Cl ) 3 GeCl where Ph Cl denotes Cl 5 C 6 ) with Ph Cl MgCl give perchloro(2,2′-biphenylene)diphenyl-silane ( 2 ) and -germane ( 3 ), respectively. The structure of both strained compounds have been determined by X-ray crystallography of their benzene solvates. The photobromination of germane 3 with Br 2 results in cleavage of one germanium-biphenylene bond to give the highly crowded bromo(2-(2′-bromooctachlorobiphenyl))bis(pentachlorophenyl)germane ( 4 ).

A novel class of aza-analogues of sesquifulvalene with a betaine character: 1-alkyl-4-(azolylidene)-1,4-dihydropyridines

The first synthesis of 1-alkyl-4-(azolylidene)-1,4-dihydropyridines(2A)↔(2B) is described; their physicochemical properties clearly indicate a significant contribution of the dipolar structure(2B) to the ground state of (2) and this has been confirmed by the X-ray crystal structure of 1-methyl-4-(benzimidazolylidene)-1,4-dihydropyridine(4a).

Synthesis of the first example of a cyclometallated ortho-nitrophenyl complex. X-Ray molecular structure of carbonyl(chloro)bis(o-nitrophenyl-C,O)rhodium

The complex [RhCl(CO)2]2 reacts at room temperature with [Hg(2-C6H4NO2)2](1:2) to give metallic mercury and the complex [[graphic ommitted])2Cl(CO)] whose crystal structure shows an octahedral co-ordination with one oxygen atom of each nitrophenyl ligand co-ordinated to the rhodium atom.

Perchlorophenyl-silicon compounds. Crystal and molecular structure of perchlorotriphenylsilane

The synthesis of tris(pentachlorophenyl)silane (1), perchlorotriphenylsilane (2), and bromotris(pentachlorophenyl)silane (3) are reported for the first time, the hydrolysis of (2) and (3) under neutral conditions giving tris(pentachlorophenyl)silanol (4); the structure of the silane (2) has been established by X-ray crystallography.