Molecular and Crystal Structure of an Organoplatinum(II) Complex with Dipyrido[3,2-a : 2′,3′-c]phenazine (dppz)

The dimesitylplatinum(II) complex PtMes₂(dppz) (Mes = mesityl = 2,4,6-trimethylphenyl) crystallizes with one equivalent of toluene (C₄₃H₄₀N₄Pt, monoclinic, P2₁/c, Z = 4, a = 14.3551(14) Å, b = 15.8319(14) Å, c = 15.369(2) Å, β = 96.784(6)°). The (dppz)Pt(C1_Mes)₂ part of the molecule was found to be planar, the mesityl substituents adopting dihedral angles of 70.3° and 85.5° with that plane. The photoemissive and reversibly reducible and oxidizable complex molecules form pairs in the crystal with the planar phenazine π “tails” overlapping in graphite-like fashion at 3.427 Å distance. The results are discussed in comparision with a recently reported structure of PtCl₂(dppz).     

Synthesis,reactivity and crystal structure of trimesitylgermylamine,Mes3GeNH2

Trimesitylgermylamine, Mes₃GeNH₂, prepared in high yield by the coupling of Mes₃GeCl (Mes  2,4,6-Me₃C₆H₂) with NaNH₂ or LiNH₂, has been fully characterized by ¹H and ¹³C NMR, IR and mass spectrometry. It is a rare example of a stable primary germylamine, melting at 166°C, which is only slowly cleaved by H₂O, CH₃OH, HCl or phenol, indicating that the central Ge atom is protected from attack by the mesityl groups. Unlike other germylamines, Mes₃GeNH₂ reacts with ^tBuCOCl to give the N-substituted amide, Mes₃GeNHCO^tBu, rather than Mes₃GeCl. Preliminary X-ray crystallographic analyses reveal that the Ge atom has approximate tetrahedral coordination with an average GeC bond length of 1.978(3) Å and a GeN bond length of 1.854(3) Å, and crowding around the Ge atom so that it is shielded from attack by approaching reactants.     

π–π Dimerization of a mono(pyridyl–imine) platinum(II) chelate

The cation of the title complex salt, chlorido{2,2‐dimethyl‐N‐[(E)‐1‐(pyridin‐2‐yl)ethylidene]propane‐1,3‐diamine}platinum(II) tetrafluoridoborate, [PtCl(C₁₂H₁₉N₃)]BF₄, exhibits a nominally square‐planar Pt^II ion coordinated to a chloride ion [Pt—Cl = 2.3046 (9) Å] and three unique N‐atom types, viz. pyridine, imine and amine, of the tridentate Schiff base ligand formed by the 1:1 condensation of 1‐(pyridin‐2‐yl)ethanone and 2,2‐dimethylpropane‐1,3‐diamine. The cations are π‐stacked in inversion‐related pairs (dimers), with a mean plane separation of 3.426 Å, an intradimer Pt...Pt separation of 5.0785 (6) Å and a lateral shift of 3.676 Å. The centroid (Cg) of the pyridine ring is positioned approximately over the Pt^II ion of the neighbouring cation (Pt...Cg = 3.503 Å).     

Diiodobis(diphenyltelluride)mercury(II), [(Ph2Te)2HgI2]

Diiodobis(diphenyltelluride)mercury(II), [(Ph₂Te)₂HgI₂], is formed during the reaction of [(PhTe)₂Hg] with HgI₂ in refluxing THF. The same product can be obtained from a pressure reaction between PhTeI₃ and elemental mercury. The mercury atom is co‐ordinated in a distorted tetrahedral environment with I‐Hg‐I angles of 117?. Long range I···Te contacts of about 3.8 Å link the [(Ph₂Te)₂HgI₂] units to infinite chains along the b axis of the unit cell.     

Twinning by merohedry in bis(4‐methoxyphenyl)tellurium(IV) diiodide dimethyl sulfoxide hemisolvate

Green crystals of the title compound, C₁₄H₁₄I₂O₂Te·0.5C₂H₆OS, space group P3₂, show twinning by merohedry (class II). The asymmetric unit contains two organotellurium molecules and one dimethyl sulfoxide (DMSO) molecule. The crystal structure displays secondary Te...I and Te...O(DMSO) bonds that lead to [(4‐MeOC₆H₄)₂TeI₂]₂·DMSO supramolecular units in which the two independent organotellurium molecules are bridged by the DMSO O atom. In addition to these secondary bonds, I...I interactions link translationally equivalent organotellurium molecules to form nearly linear ...I—Te—I...I—Te—I... chains. These chains are crosslinked, forming two‐dimensional arrays parallel to (001). The crystal packing consists of a stacking of these sheets, which are related by the 3₂ axis. This study describes an unusual dimeric arrangement of X—Te—X groups.     

Structural Diversity of Calcium Organocuprates(I): Synthesis of Mesityl Cuprates via Addition and Transmetalation Reactions of Mesityl Copper(I)

The addition of [(L)₄Ca(I)Mes] (Lewis base L=thf, Et₂O) to mesityl copper(I) and the transmetalation reaction of mesityl copper(I) with activated calcium are suitable pathways for the synthesis of dimesityl cuprates(I) of calcium. However, the structures of the calcium cuprates(I) depend on the preparative procedure. The transmetalation reaction leads to the formation of [Mes‐Cu‐Mes]^? anions whereas the addition yields dinuclear [(Mes‐Cu)₂(μ‐Mes)]^? anions. The solvent‐separated counterions are [Ca(thf)₆]²⁺ and [(thf)₅CaI]⁺, respectively. In contrast to these findings, the addition of [(L)₄Ca(I)Mes] to mesityl copper(I) in an Et₂O/toluene mixture led to formation of tetrameric solvent‐free iodocalcium dimesityl cuprate(I) [ICa(μ‐η¹,η⁶‐Mes₂Cu)]₄, representing a rare example of a heavy Normant‐type organocuprate.     

The first crystal structures of six‐ and seven‐membered tellurium‐ and nitrogen‐containing (Te—N) heterocycles: 2H‐1,4‐benzotellurazin‐3(4H)‐one and 2,3‐dihydro‐1,5‐benzotellurazepin‐4(5H)‐one

There is a paucity of data concerning the structures of six‐ and seven‐membered tellurium‐ and nitrogen‐containing (Te—N) heterocycles. The title compounds, C₈H₇NOTe, (I), and C₉H₉NOTe, (II), represent the first structurally characterized members of their respective classes. Both crystallize with two independent molecules in the asymmetric unit. When compared to their sulfur analogs, they exhibit slightly greater deviations from planarity to accommodate the larger chalcogenide atom, with (II) adopting a pronounced twist‐boat conformation. The C—Te—C angles of 85.49 (15) and 85.89 (15)° for the two independent molecules of (I) were found to be somewhat smaller than those of 97.4 (2) and 97.77 (19)° for the two independent molecules of (II). The C—Te bond lengths [2.109 (4)–2.158 (5) Å] are in good agreement with those predicted by the covalent radii. Intermolecular N—H...O hydrogen bonding in (I) forms centrosymmetric R₂²(8) dimers, while that in (II) forms chains. In addition, intermolecular Te...O contacts [3.159 (3)–3.200 (3) Å] exist in (I).     

Crystallographic report: [1,3‐Di(mestityl)imidazol‐2‐ylidene]gallium iodide dihydride

The structure of the N‐heterocyclic gallium hydride complex, [GaH₂I{CN(Mes)C₂H₂N(Mes)}], Mes = mesityl, shows both hydride ligands to be bonded to the distorted tetrahedral gallium centre. Copyright © 2003 John Wiley & Sons, Ltd.     

A Sterically Hindered Phosphonic Acid with a Hydrogen‐Bonded Cage Structure: [4‐tert‐Bu‐2,6‐Mes2‐C6H2P(O)(OH)2·H2O]4

The synthesis and molecular structure of the novel phosphonic acid 4‐tert‐Bu‐2,6‐Mes₂‐C₆H₂P(O)(OH)₂ ( 1 ) is reported. Compound 1 crystallizes in form of its monohydrate as a hydrogen‐bonded cluster ( 1·H₂O )₄ comprizing four phosphonic acid molecules (O···O 2.383(3)‐3.006(4) Å). Additionally, sterically hindered terphenyl‐substituted phosphorus compounds of the type 4‐tert‐Bu‐2,6‐Mes₂‐C₆H₂PR(O)(OH) ( 5 , R = H; 7 , R = O₂CC₆H₄‐3‐Cl; 9 , R = OEt) were prepared, which all show dimeric hydrogen‐bonded structures with O···O distances in the range 2.489(2)–2.519(3) Å. Attempts at oxidizing 5 using H₂O₂, KMnO₄, O₃, or Me₃NO in order to give 1 failed. Crystallization of 5 in the presence of Me₃NO gave the novel hydrogen bonded aggregate 4‐tert‐Bu‐2,6‐Mes₂‐C₆H₂PH(O)(OH)·ONMe₃ ( 6 ) showing an O–H···O distance of 2.560(4) Å.     

Synthesis,Spectroscopic Properties,and Crystal Structure of 2,2′‐Bipyridyldimesitylnickel(II)

The dimesitylnickel(II) complex [(bpy)NiMes₂] (Mes = mesityl = 2,4,6‐trimethylphenyl) was prepared and examined spectroscopically and electrochemically. The crystal and molecular structure was determined from single crystal X‐Ray diffraction experiments (monoclinic, P2₁/n, Z = 4, a = 8.3092(8) Å, b = 18.233(2) Å, c = 15.226(2) Å, β = 98.035(6)°). The nickel atom displays a distorted square planar environment. The axial positions of the square plane are shielded by each one of the methyl groups on the mesityl substituents. The complex shows electrochemical reduction processes that are mainly centered on the bpy ligand as inferred from spectroelectrochemical investigations (EPR and UV/Vis/NIR absorption) of the radical anion or dianion. The observed oxidation is assigned to a Ni^II/Ni^III couple. The title complex exhibits strongly solvatochromic longwavelength electronic absorptions.     

cis-Bis(di­methyl sulfoxide-S)­dinitrato­palladium(II) and cis-dinitratobis(1,4-oxathiane-S)­palladium(II)

The Pd atom in each of the two title compounds, [Pd(NO₃)₂(C₂H₆OS)₂], (I), and [Pd(NO₃)₂(C₄H₈OS)₂], (II), coordinates two O atoms from two nitrate ligands and two S atoms from di­methyl sulfoxide (dmso) and thio­xane (systematic name: 1,4-oxathiane) ligands in a pseudo-square-planar cis-geometry. In the dmso complex, the distances to palladium are Pd—O 2.067 (2) and 2.072 (2) Å, and Pd—S 2.2307 (11) and 2.2530 (8) Å. The corresponding distances in the thio­xane complex are Pd—O 2.053 (3) and 2.076 (2) Å, and Pd—S 2.2595 (9) and 2.2627 (11) Å. Both compounds may be regarded as dimers with an inversion centre, where one of the coordinating nitrate O atoms in one mol­ecule also interacts with the Pd atom in the adjacent mol­ecule, with Pd—O distances of 2.849 (9) and 3.31 (3) Å in (I) and (II), respectively.     

Bis(2,4,6‐trimethylphenyl)tellurium(IV) Dicyanide: the First Crystal Structure for a Tellurium Cyanide of the Type R2Te(CN)2

The reaction of Mes₂TeF₂ (Mes = 2,4,6‐trimethylphenyl) with trimethylsilyl cyanide yields the corresponding tellurium(IV) dicyanide Mes₂Te(CN)₂. Isolation of suitable crystals allows the determination of the first crystal structure of a compound of the type R₂Te(CN)₂.     

Chlorotris(2,4,6‐trimethylphenyl)tin(IV) and its ethanol hemisolvate

Chloro­tris(2,4,6‐tri­methyl­phenyl)­tin(IV), crystallizes from ethanol as solvent‐free needles, [Sn(C₉H₁₁)₃Cl], (I), and as the hemisolvate, [Sn(C₉H₁₁)₃Cl]·0.5C₂H₆O, (II). The asymmetric unit in (I) has three independent mol­ecules, whereas in (II), there are two [Sn(C₉H₁₁)₃Cl] mol­ecules together with one ethanol molecule. In the unit cell of (II), the ethanol mol­ecules lie in channels between stacks of (Mes)₃SnCl mol­ecules (Mes is 2,4,6‐tri­methyl­phenyl) and each ethanol mol­ecule is disordered (0.50:0.50) over two positions. A comparison of the structures of the title compounds and other (Mes)₃SnX (X = F, Br or I) systems with those of the tri­phenyl­tin analogues shows that the steric requirements of the o‐CH₃ groups are met by a flattening of the SnC₃ skeleton and increases in the average Sn—X and Sn—C values. Comparing Sn—X data for (Mes)₃SnX (X = F, Cl, Br or I) systems with values for the tris(o‐methoxy­phenyl)­tin analogues suggests that the Sn—F distance of 1.961 Å in (Mes)₃SnF may well be characteristic of sterically unhindered four‐coordinate Ar₃SnF systems.     

Triphenylphosphinoxid (L) als Solvens und Ligand für Metallphthalocyaninate; Synthese und Struktur von [{Li(L)}2(μ‐pc)], [Li(L)4][Lipc] · Solvat, [Mg(L)pc] · Solvat und [Zn(L)pc] · Solvat

Triphenylphosphine Oxide (L) as Solvent and Ligand for Metallophthalocyaninates; Synthesis and Structure of [{Li(L)}₂(μ‐pc)], [Li(L)₄][Lipc] · Solvate, [Mg(L)pc] · Solvate, and [Zn(L)pc] · Solvate Triphenylphosphine oxide (L) coordinates to metallophthalocyaninates of Li, Mg and Zn at 300 °C. After purification and recrystallization in different solvents the very soluble and stable title compounds have been isolated and structurally characterized. In [{Li(L)}₂(μ‐pc)], the Li atom lies in a distorted tetragonal pyramid of four isoindole N atoms (N_i) at a distance varying between 2.163(5) and 2.301(5) Å, and an O atom at 1.863(5) Å. In [Li(L)₄] · [Lipc] · S, the Li atom of the cation coordinates four O atoms in a distorted tetrahedral arrangement at a distance varying from 1.887(9) to 1.953(9) Å, while the Li atom of the anion is in a quasi quadratic planar geometry of four N_i atoms (1.951(9)–1.977(9) Å) with the Li atom being displaced by 0.15 Å out of the (N_i)₄ plane. The structural data of the distorted tetragonal pyramidale Mg(N_i)₄O moiety in [Mg(L)pc] and the solvates [Mg(L)pc] · S (S = CH₂Cl₂, thf, 2py) generally do not vary significantly: Mg–N_i/2.035(3) –2.061(3) Å, Mg–O/1.955(2)–2.000(3) Å. The Mg atom is displaced by ca. 0.52 Å out of the (N_i)₄ plane towards the O atom and the Mg–O–P moiety is bent (ca. 153°). [Zn(L)pc] · S crystallizes as a mixed crystal of equal parts of the conformer with a bent (155.1(3)°) and that of a quasi linear Zn–O–P moiety (174.2(3)°). Structural data of the Zn(N_i)₄O moiety: (Zn–N_i)_av: 2.024/2.013 Å; Zn–O: 2.050(4)/2.081(4) Å; Zn–(N_i)₄: 0.40/0.33 Å. In the crystal, the Mg and Zn derivates aggregate in double layers forming pairs. The pc ligands in the triclinic complexes with good overlap of the neighbouring pc ligands are in a waving conformation, while those in the monoclinic complexes with weak overlap are in a concave conformation.     

Benzyl­triethyl­ammonium 2,2,2,4‐tetra­chloro‐2,5‐di­hydro‐1,2λ5‐oxatellurole

The geometry around the Te atom in the anion in C₁₃H₂₂N⁺·C₃H₃Cl₄OTe^? is distorted pseudo‐octahedral with three Cl atoms and the O atom forming the equatorial plane, and the C atom lying opposite the tellurium lone pair. Distances and angles are: Te—O 2.0120 (18), Te—C 2.072 (2), Te—Cl 2.5239 (7), 2.5283 (7) and 2.5577 (7) Å; O—Te—C 81.61 (9), O—Te—Cl 90.69 (6), 90.99 (6) and 168.13 (5), C—Te—Cl 87.13 (8), 86.64 (8) and 86.59 (8), and Cl—Te—Cl 87.02 (2), 90.00 (3) and 173.24 (3)°. The anions are arranged in an infinite zigzag chain parallel to the a axis through a secondary Te?Cl bond [3.8391 (8) Å].     

A new polymorph of 1‐ferrocenyl‐3‐(3‐nitroanilino)propan‐1‐one

Recrystallization of the title compound, [Fe(C₅H₅)(C₁₄H₁₃N₂O₃)], from a mixture of n‐hexane and dichloromethane gave the new polymorph, denoted (I), which crystallizes in the same space group (P) as the previously reported structure, denoted (II). The Fe—C distances in (I) range from 2.015 (3) to 2.048 (2) Å and the average value of the C—C bond lengths in the two cyclopentadienyl (Cp) rings is 1.403 (13) Å. As indicated by the smallest C—Cg1—Cg2—C torsion angle of 1.4° (Cg1 and Cg2 are the centroids of the two Cp rings), the orientation of the Cp rings in (I) is more eclipsed than in the case of (II), for which the value was 15.3°. Despite the pronounced conformational similarity between (I) and (II), the formation of self‐complementary N—H...O hydrogen‐bonded dimers represents the only structural motif common to the two polymorphs. In the extended structure, molecules of (I) utilize C—H...O hydrogen bonds and, unlike (II), an extensive set of intermolecular C—H...π interactions. Fingerprint plots based on Hirshfeld surfaces are used to compare the packing of the two polymorphs.     

Structures of Iodophenyltellurium(II) and Diiododi-(β-naphtyl)tellurium(IV)

The reactions between diphenyl ditelluride, (PhTe)₂, or di(β-naphtyl)ditelluride, (β-naphtylTe)₂, with equivalent amounts of iodine have been reinvestigated and the crystal and molecular structures of iodophenyltellurium(II), (PhTeI)₄, and diiododi-(β-naphtyl)tellurium(IV), (β-naphtyl)₂TeI₂, have been determined. The structure of iodophenyltellurium(II) (space group Cc, a = 13.850(5) Å, b = 13.852(3) Å, c = 16.494(6) Å and β = 101.69(2)°, Z = 4) is built up by four PhTeI units which are linked by weak Te–Te interactions with Te–Te distances between 3.152(5) Å and 3.182(4) Å. The angles between the tellurium atoms are approximately 90° giving an almost perfect square. Long range secondary bonds (Te–I: about 4.2 Å) link the tetrameric units to give an infinite two-dimensional network. Iodo(β-naphtyl)tellurium(II) is less stable than the phenyl derivative. Solutions of this compound decompose under formation of elemental tellurium and (β-naphtyl)₂TeI₂. (β-Naphtyl)₂TeI₂ crystallises in the monoclinic space group C 2/c (a = 21.198(6) Å, b = 5.8921(8) Å, c = 16.651(5) Å, β = 114.77(2)°). The tellurium atom is situated on a two-fold crystallographic axis and Te–I and Te–C bond lengths of 2.899(1) and 2.108(7) Å have been determined.     

trans‐Tetrachlorobis(N,N′‐dimethyl­imidazolidine‐2‐thione)tellurium(IV), a thiourea complex of tellurium with asymmetric Te—S bonds

The structure of the title compound, [TeCl₄(C₅H₁₀N₂S)₂] or C₁₀H₂₀Cl₄N₄S₂Te, has been solved in order to study the stereochemical activity of the lone pair of electrons on Te^IV. The two crystallographically independent mol­ecules in the asymmetric unit both show a distorted octahedral coordination of the Te atom. The two Te—S bonds are trans to each other in both mol­ecules and are greatly asymmetric, with bond lengths of 2.5686 (7) versus 2.8557 (8) Å and 2.5859 (7) versus 2.8165 (9) Å. The Te—Cl bond lengths lie in the range 2.5236 (7)–2.5589 (8) Å. The asymmetric Te—S bonds and a large S—Te—Cl angle of ca 97° involving the long Te—S bonds indicate stereochemical activity of the lone pair of electrons on Te.     

Dimeric (isoquinoline)(N‐salicylidene‐d,l‐glutamato)copper(II) ethanol solvate

The title racemic complex, bis[μ‐N‐(2‐oxidobenzylidene)‐d ,l ‐glutamato(2−)]bis[(isoquinoline)copper(II)] ethanol disolvate, [Cu₂(C₁₂H₁₁NO₅)₂(C₉H₇N)₂]·2C₂H₆O, adopts a square‐pyramidal Cu^II coordination mode with a tridentate N‐salicylideneglutamato Schiff base dianion and an isoquinoline ligand bound in the basal plane. The apex of the pyramid is occupied by a phenolic O atom from the adjacent chelate molecule at an apical distance of 2.487 (3) Å, building a dimer located on the crystallographic inversion center. The Cu...Cu spacing within the dimers is 3.3264 (12) Å. The ethanol solvent molecules are hydrogen bonded to the dimeric complex molecules, forming infinite chains in the a direction. The biological activity of the title complex has been studied.     

Syntheses and Crystal Structures of Two Novel Linear Trinuclear Schiff Base Nickel(II) and Cadmium(II) Complexes

Two novel linear trinuclear Schiff base complexes, [Ni{Ni(C₁₇H₁₄Br₂N₂O₂)(NO₃)(H₂O)}₂] · 2MeOH · 2H₂O ( 1 ), and [Cd{Ni(C₂₅H₂₀N₂O₂)(CH₃COO)}₂] ( 2 ), were synthesized and characterized by elemental analyses, infrared spectroscopy, and X‐ray single crystal determinations. There are three bridges across the Ni‐M atom pairs (M is Ni for 1 , and Cd for 2 ) in each complex, involving two phenolate O atoms of a Schiff base ligand (N,N′‐bis(5‐bromosalicylidene)‐1,3‐propanediaminate (BSPD) for 1 and N,N′‐bis(2‐hydroxynaphthylmethenylimino)‐1,3‐propanediaminate (HNPD) for 2 ), and an O‐N‐O moiety of a μ‐nitrato group for 1 or an O‐C‐O moiety of a μ‐acetato group for 2 . In each of the complexes, the central M²⁺ is located on an inversion center and has an octahedral coordination involving four bridging O atoms from two Schiff base ligands in the equatorial plane and one O atom from each bridging nitrate or acetate group in the axial positions. The coordination around the terminal Ni²⁺ ions is also octahedral for 1 , but square pyramidal for 2 . The nitrate or acetate bridges linking the central and terminal metal ions are mutually trans. The Ni···M distances are 3.006(2) Å in 1 , and 3.175(2) Å in 2 .