bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper(I) and Gold(I) Complexes with N,N′‐Bis(diphenylphosphino)‐2,6‐diaminopyridine as Ligand: Synthesis and Molecular Structures
Authors: Pan Zhida , Gamer Michael T. , Roesky Peter W. 
Published: March 2006

AbstractReaction of CuI with 1 or 2 equivalent(s) N,N′‐Bis(diphenylphosphino)‐2,6‐diaminopyridine (BDDP) gives two different complexes, [Cu(I)μ‐(BDDP‐κP,Npy)]2 (1) and [Cu(BDDP‐κP,Npy)2]I (2), in high yields. The determination of the molecular structure show that both CuI atoms are tetrahedrally coordinated, rather than a square‐planar geometry reported for Cr0, NiII‐BDDP complexes before, which contains a planar tridentate chelate ring system. The introduction of AuCl(tht) (tht = tetrahydrothiophene) into [Cu(BDDP‐κP,Npy)2]I leads unexpectedly to the formation of a digold complex 2,6‐[(ClAuPh2P)HN]2C5H3N and dimeric [Cu(I)μ‐(BDDP‐κP,Npy)]2.
Preparation and Characterization of Dinuclear Chromium(III) Complexes of a Hexadentate Tetraaza‐Dithiophenolate Ligand
Authors: Siedle Gabriel , Kersting Berthold 
Published: March 2006

AbstractThe ability of the tetraaza‐dithiophenolate ligand H2L2 (H2L2 = N,N′‐Bis‐[2‐thio‐3‐aminomethyl‐5‐tert‐butyl‐benzyl]propane‐1,3‐diamine) to form dinuclear chromium(III) complexes has been examined. Reaction of CrIICl2 with H2L2 in methanol in the presence of base followed by air‐oxidation afforded cis,cis‐[(L2)CrIII2(μ‐OH)(Cl)2]+ (1a) and trans,trans‐[(L2)CrIII2(μ‐OH)(Cl)2]+ (1b). Both compounds contain a confacial bioctahedral N2ClCrIII(μ‐SR)2(μ‐OH)CrIIIClN2 core. The isomers differ in the mutual orientation of the coligands and the conformation of the supporting ligand. In 1a both Cl− ligands are cis to the bridging OH function. In 1b they are in trans‐positions. Reaction of the hydroxo‐bridged complexes with HCl yielded the chloro‐bridged cations cis,cis‐[(L2)CrIII2(μ‐Cl)(Cl)2]+ (2a) and trans,trans‐[(L2)CrIII2(μ‐Cl)(Cl)2]Cl (2b), respectively. These bridge substitutions proceed with retention of the structures of the parent complexes 1a and 1b.
Synthese, Kristallstruktur und spektroskopische Charakterisierung von [Au12(PPh)2(P2Ph2)2(dppm)4Cl2]Cl2
Authors: Sevillano Paloma , Fuhr Olaf , Matern Eberhard , Fenske Dieter 
Published: March 2006

AbstractSynthesis, Crystal Structure and Spectroscopic Characterization of [Au12(PPh)2(P2Ph2)2(dppm)4Cl2]Cl2The reaction of [(AuCl)2dppm] (dppm = Ph2PCH2PPh2) with P(Ph)(SiMe3)2 in CHCl3 results in the formation of [Au12(PPh)2(P2Ph2)2(dppm)4Cl2]Cl2 (1), the crystal structure of which was determined by single crystal X‐ray analysis (space group P21/c, a = 1425.3(3) pm, b = 2803.7(6) pm, c = 2255.0(5) pm, β = 95.00(3)°, V = 8977(3)·106 pm3, Z = 2). The dication in 1 consists of two Au6P3 units built by highly distorted Au3P and Au2P2 heterotetrahedra, connected via four bidentate phosphine ligands. Additionally, the compound was characterized by IR‐, UV‐ and NMR spectroscopy. The 31P{1H} NMR spectrum is discussed in detail.
Die Reaktion des Digalliumsubiodids R(I)Ga‐Ga(I)R [R = C(SiMe3)3] mit Lithium‐diphenylphosphanid – radikalische Öffnung der Ga‐Ga‐Bindung
Authors: Uhl Werner , El‐Hamdan Abdel Hakim 
Published: March 2006

AbstractThe Reaction of the Digallium Subiodide R(I)Ga‐Ga(I)R [R = C(SiMe3)3] with Lithium Diphenylphosphanide – Radical Cleavage of the Ga‐Ga BondThe easily available organoelement digallium(II) subiodide R(I)Ga‐Ga(I)R (1) [R = C(SiMe3)3] reacted with two equivalents of lithium diphenylphosphanide in toluene by the replacement of both iodine atoms by two phosphanido groups. The product, [R(H)Ga‐P(C6H5)2]2 (2), contains a four‐membered Ga2P2 heterocycle without direct Ga‐Ga bonding interactions and the gallium atoms exclusively in an oxidation state of +III. They are attached to hydrogen atoms, which may result from a reaction of a reactive intermediate with the solvent.
Synthese, Struktur und Eigenschaften der Komplexe [(H2O)Cl4Os≡N‐IrCl(C5Me5)(AsPh3)], [(Ph3Sb)Cl4Os≡N‐IrCl(C5Me5)(SbPh3)], [(Ph3Sb)2Cl3Os≡N‐IrCl(COD)] und [{(Me2PhP)2(CO)Cl2Re≡N}2ReNCl2(PMe2Ph)]
Authors: Morrogh Daniel , Schwarz Simon , Maichle‐Mössmer Cäcilia , Strähle Joachim 
Published: March 2006

AbstractSynthesis, Crystal Structure, and Properties of the Complexes [(H2O)Cl4Os≡N‐IrCl(C5Me5)(AsPh3)], [(Ph3Sb)Cl4Os≡N‐IrCl(C5Me5)(SbPh3)], [(Ph3Sb)2Cl3Os≡N‐IrCl(COD)] and [{(Me2PhP)2(CO)Cl2Re≡N}2ReNCl2(PMe2Ph)]The dinuclear complexes [(H2O)Cl4Os≡N‐IrCl(C5Me5)(AsPh3)]·H2O (1·H2O), [(Ph3Sb)Cl4Os≡N‐IrCl(C5Me5)(SbPh3)] (2), and [(Ph3Sb)2Cl3Os≡N‐IrCl(COD)] (3) result from the reaction of the nitrido complexes [(Ph3As)2OsNCl3] and [(Ph3Sb)2OsNCl3] with the iridium compounds [IrCl2(C5Me5)]2 and [IrCl(COD)]2 in dichloromethane. 1 crystallizes as 1·H2O in form of green platelets in the monoclinic space group Cm and a = 1105.53(6); b = 1486.76(9); c = 2024.88(10) pm, β = 97.191(4)°, Z = 4. The formation of 1 in air involves a ligand exchange, and the coordination of a water molecule in trans position to the Os‐N triple bond. The resulting complex fragments [(H2O)Cl4Os≡N] and [IrCl(C5Me5)(AsPh3)] are connected by an asymmetric nitrido bridge Os≡N‐Ir. The nitrido bridge is characterised by an Os‐N‐Ir bond angle of 173.7(7)°, and distances Os‐N = 168(1) pm and Ir‐N = 191(1) pm. 2 crystallizes in clumped together brown platelets with the space group ${\rm P}{\bar 1}$ and a = 1023.3(3), b = 1476.2(3), c = 1872.5(6) pm, α = 74.60(2), β = 73.84(2), γ = 76.19(2)°, Z = 2. In 2 the asymmetric nitrido bridge Os≡N‐Ir joins the two complex fragments [(Ph3Sb)Cl4Os≡N] and [IrCl(C5Me5)(SbPh3)], which are formed by a ligand exchange reaction. 3 forms dark green crystals with the triclinic space group ${\rm P}{\bar 1}$ and a = 1079.4(1), b = 1172.3(1), c = 1696.7(2) pm, α = 101.192(9),β = 92.70(1), γ = 92.61(1)°, Z = 2. The distances in the almost linear nitrido bridge (Os≡N‐Ir = 175.3(7)°) are Os‐N = 171(1) pm and Ir‐N = 183(1) pm. The reaction of [ReNCl2(PMe2Ph)3] with [Mo(CO)3(NCMe)3] unexpectedly affords the trinuclear complex [{(Me2PhP)2(OC)Cl2Re≡N}2ReNCl2(PMe2Ph)] (4) as the main product. It forms triclinic brown crystals with the composition 4·2THF and the space group ${\rm P}{\bar 1}$ (a = 1382.70(7), b = 1498.58(7), c = 1760.4(1) pm, α = 99.780(7), β = 99.920(7), γ = 114.064(6)°, Z = 2). In the trinuclear complex, the central fragment, [ReNCl2(PMe2Ph)] is joined in trans position to two nitrido complexes [(Me2PhP)2(CO)Cl2Re≡N], giving an almost linear Re≡N‐Re‐N≡Re arrangement. The bond angles and distances in the nitrido bridges are Re‐N‐Re = 167.8(3)°, Re‐N = 171.1(8) pm and 204.2(8) pm; and Re‐N‐Re = 168.1(4)°, Re‐N = 170.9(9) and 203.5(9) pm respectively. As expected, the Re‐N bond length to the terminal nitrido ligand on the central Re atom is much shorter at 161.2(9) pm than the triple bonds of the asymmetric bridges.
A Diazabutadiene stabilized Nickel(0) Cyclooctadiene Complex: Synthesis, Characterization and the Reaction with Diphenylacetylene
Authors: Schaub Thomas , Radius Udo 
Published: March 2006

AbstractThe reaction of [Ni(COD)2] with one equivalent of DABMes (DABMes = (2,4,6‐Me3C6H2)N=C(Me)‐C(Me)=N(2,4,6‐Me3C6H2)) affords a mixture of the compound [Ni(DABMes)2] (2) and starting material [Ni(COD)2]. The crystallographically characterized, diamagnetic complex 2 can be obtained in a stoichiometric reaction of [Ni(COD)2] and two equivalents of DABMes. This reaction can be accelerated by addition of 1‐chloro‐fluorobenzene or methyl iodide. In the presence of 1‐chloro‐fluorobenzene, [Ni(DABMes)(COD)] (3) is available via reaction of [Ni(COD)2] and one equivalent of DABMes. The crystallographically characterized complex 3 reacts with diphenylacetylene to afford [Ni(DABMes)(Ph‐C≡C‐Ph)] (4). A long‐wavelength absorption band in the UV‐Vis spectrum of this compound has to be assigned to a mixed MLCT/LL′CT transition, as quantum chemical calculations reveal.
Theoretical Studies of Inorganic Compounds. 361) Structures and Bonding Analyses of Beryllium Chloro Complexes with Nitrogen Donors
Authors: Metz Sebastian , Holthausen Max C. , Frenking Gernot 
Published: March 2006

AbstractQuantum chemical calculations at various levels of theory (BP86, B3LYP, MP2, CCSD(T), CBS‐QB3) of the beryllium complexes [BeCl2(NHPH3)], [BeCl2(NHPH3)2], [BeCl3(py)]−, [BeCl2(NH3)], [BeCl2(NH3)2], [BeCl3(py)]− and [BeCl3(NH3)]− as well as the boron compounds [BCl3(py)] and [BCl3(NH3)] show that BeCl2 is a very strong Lewis acid. The theoretically predicted bond dissociation energy at CBS‐QB3 of Cl2Be‐NH3 (De = 32.5 kcal/mol)is even higher than that of Cl3B‐NH3 (De = 28.6 kcal/mol). Even the second ammonia molecule in [BeCl2(NH3)2] still has a strong bond with De = 24.2 kcal/mol. The theoretically predicted bond strengths for the phosphaneimine ligands in [BeCl2(NHPH3)2] are De = 46.7 kcal/mol for the first ligand and De = 29.8 kcal/mol for the second. The anion BeCl3− is a moderately strong Lewis acid which has bond energies of De = 14.1 kcal/mol in [BeCl3(py)]− and De = 14.2 kcal/mol in [BeCl3(NH3)]−. The higher bond energy of [BeCl2(NH3)] compared with [BCl3(NH3)] comes from less deformation energy for BeCl2 than for BCl3. The intrinsic attraction between BeCl2 and NH3 calculated with frozen geometries of the complex geometry is ∼5 kcal/mol less than the attraction between BCl3 and NH3. The bonding analysis with the EDA method shows that the attractive energy of the beryllium complexes comes manly from electrostatic attraction. The larger contribution of the electrostatic term is the most significant difference between the nature of the donor‐acceptor bonds of the beryllium and boron complexes.
Influence of the Counterions on the Structures of Ternary Zn/Sn/Se Anions: Synthesis and Properties of [Rb10(H2O)14.5][Zn4(μ4‐Se)2(SnSe4)4] and [Ba5(H2O)32][Zn5Sn(μ3‐Se)4(SnSe4)4]
Authors: Ruzin Eugen , Dehnen Stefanie 
Published: March 2006

AbstractReactions of rubidium or barium salts of the ortho‐selenostannate anion, [Rb4(H2O)4][SnSe4] (1) or [Ba2(H2O)5][SnSe4] (2) with Zn(OAc)2 or ZnCl2 in aqueous solution yielded two novel compounds with different ternary Zn/Sn/Se anions, [Rb10(H2O)14.5][Zn4(μ4‐Se)2(SnSe4)4] (3) and [Ba5(H2O)32][Zn5Sn(μ3‐Se)4(SnSe4)4] (4). 1 – 4 have been determined by means of single crystal X‐ray diffraction: 1: triclinic space group $P{\bar 1}$ lattice dimensions at 203 K: a = 8.2582(17) Å, b = 10.634(2) Å, c = 10.922(2) Å, α = 110.16(3)°, β = 91.74(3)°, γ = 97.86(3)°, V = 888.8(3) Å3; R1 [I > 2σ(I)] = 0.0669; wR2 = 0.1619; 2: orthorhombic space group Pnma; lattice dimensions at 203 K: a = 17.828(4) Å, b = 11.101(2) Å, c = 6.7784(14) Å, V = 1341.5(5) Å3; R1 [I > 2σ(I)] = 0.0561; wR2 = 0.1523; 3: triclinic space group $P{\bar 1}$; lattice dimension at 203 K: a = 17.431(4) Å, b = 17.459(4) Å, c = 22.730(5) Å, α = 105.82(3)°, β = 99.17(3)°, γ = 90.06(3)°, V = 6563.1(2) Å3; R1 [I > 2σ(I)] = 0.0822; wR2 = 0.1782; 4: monoclinic space group P21/c; lattice dimensions at 203 K: a = 25.231(5) Å, b = 24.776(5) Å, c = 25.396(5) Å, β = 106.59(3)°, V = 15215.0(5) Å3; R1 [I > 2σ(I)] = 0.0767; wR2 = 0.1734. The results serve to underline the crucial role of the counterion for the type of ternary anion to be observed in the crystal. Whereas Rb+(aq) stabilizes a P1‐type Zn/Sn/Se supertetrahedron in 3 like K+, the Ba2+(aq) ions better fit to an anionic T3‐type Zn/Sn/Se cluster arrangement as do Na+ ions. It is possible to estimate a radius:charge ratio for the stabilization of the two structural motifs.
Selten‐Erd‐Metall‐Koordinationspolymere: Synthese und Kristallstrukturen von fünf neuen Adipinaten, [M2(Adi)3(H2O)4](AdiH2)(H2O)4 (M = La, Nd), [Er(Adi)(H2O)5]Cl(H2O) und [M(Adi)(H2O)5](NO3)(H2O) (M = Gd, Er)
Authors: Bromant Claudia , Flemig Holger , Nika Wassiliki , Pantenburg Ingo , Meyer Gerd 
Published: March 2006

AbstractRare‐Earth‐Metal Coordination Polymers: Synthesis and Crystal Structures of Five New Adipinates, [M2(Adi)3(H2O)4](AdiH2)(H2O)4 (M = La, Nd), [Er(Adi)(H2O)5]Cl(H2O) and [M(Adi)(H2O)5](NO3)(H2O) (M = Gd, Er)The new rare‐earth compounds [M2(Adi)3(H2O)4](AdiH2)(H2O)4 (M = La (1), Nd (2)), [Er(Adi)(H2O)5]Cl(H2O) (3) and [M(Adi)(H2O)5](NO3)(H2O) (M = Gd (4), Er (5)) were obtained from the reaction of adipinic acid with La(OH)3·xH2O, Nd2O3, ErCl3·6H2O, Gd(NO)3·xH2O and Er2O3, respectively. Their crystal structures were determined by single‐crystal X‐ray diffraction. The coordination polymers [M2(Adi)3(H2O)4](AdiH2)(H2O)4 crystallize in the triclinic space group ${\rm P}{\bar 1}$ (no. 2) with a = 875.4(1), b = 1000.4(2), c = 1179.0(2) pm, α = 74.70(1), β = 69.85(1), γ = 86.18(2)° and Z = 1 (crystal data for M = La, (1)). The quasi‐isostructural compounds [Er(Adi)(H2O)5]Cl(H2O) (3) and [M(Adi)(H2O)5](NO3)(H2O) (M = Gd (4), Er (5)) crystallize with monoclinic symmetry, space group C2/c (no. 15) with lattice parameters of a = 1231.5(1), b = 1532.6(1), c = 895.4(1) pm, β = 123.44(1)° and Z = 4 (crystal data for (3)). The rare‐earth cations have the coordination numbers 10 (1, 2) and 9 (3, 4 and 5), respectively. The compounds [M2(Adi)3(H2O)4](AdiH2)(H2O)4 are constructed of infinite chains of edge‐sharig [MO8(H2O)2] polyhedra that are cross‐linked by adipinic acid molecules to form framework structures. In [Er(Adi)(H2O)5]Cl(H2O) (3) and [M(Adi)(H2O)5](NO3)(H2O) (M = Gd (4), Er (5)) the central cations are bridged by adipinic acid molecules in a bidentate‐chelating manner to positively charged zigzag chains. Between these the counter ions and crystal water molecules are incorporated.
Di‐Benzo‐18‐Crown‐6 and its Derivatives as Ligands in the Search for Ion Channels
Authors: Fromm Katharina M. , Bergougnant Rémi D. , Robin Adeline Y. 
Published: March 2006

AbstractBased on the previously reported one‐dimensional channel system [(H2O)⊂(DB18C6)(μ2‐H2O)2/2][(H3O)⊂(DB18C6)(μ2‐H2O)2/2]I3 (2), which is realized by stacking of crown ether molecules (DB18C6 = dibenzo‐18‐crown‐6), other synthetic approaches towards ionic channels and their results are presented in this paper. The “cutting out” approach using DB18C6 as scissor, applied on NaI, yields the compound [Na⊂(DB18C6)I(THF)][Na⊂(DB18C6)(H2O)2]I(THF)2(CHI3) (1), in high yield. It is based on a neutral and a cationic complex of sodium by DB18C6 linked via H‐bonding to give short chain fragments. The anion exchange approach, trying to replace I3− by Br3− leads to the intercalation of a cation into a DB18C6 chain in [(Me3NPh)(DB18C6)]Br3 (3). A similar reaction as for the synthesis of 2, but replacing iodide with bromine, yields finally a brominated DB18C6 ligand. In the presence of iron, the compound [(H5O2)⊂(Br4‐DB18C6)2][FeBr4], 4, is observed, in which a H5O2+‐cation is encapsuled by two brominated crown ether molecules. The absence of Fe and an excess of Br2 leads to the complexation of H3O+, and co‐crystallisation of bromine in [(H3O)⊂(Br4‐DB18C6)]Br3Br2 (5).
Reaction of S2CC(PPh3)2 with Silver Salts Containing Weakly Coordinating Anions; Preparation and Crystal Structures of [Ag6{S2CC(PPh3)2}4][BF4]6 · 9.75CH2CL2 and [Ag4{S2CC(PPh3)2}4][Al{OC(CF3)3}4]4 · 4.25C2H4Cl2
Authors: Petz Wolfgang , Neumüller Bernhard , Krossing Ingo 
Published: March 2006

AbstractThe betain‐like carbodiphosphorane CS2 adduct S2CC(PPh3)2 (1) reacts with Ag(I) salts which contain weakly coordinating anions such as [BF4]− or [Al{OC(CF3)3}4]− to produce the cluster compounds [Ag6{S2CC(PPh3)2}4][BF4]6 (2) and [Ag4{S2CC(PPh3)2}4][Al{OC(CF3)3}4]4 (3), respectively, as orange yellow crystals containing solvent molecules. In the solid state the Ag4 unit in 3 forms a tetrahedron, and in the Ag6 core of 2 two of the opposite edges of the tetrahedron are bridged by Ag+ ions. The clusters are held together by argentophilic interactions, and each sulfur atom of 1 is coordinated to four (as in 2) or three (as in 3) silver atoms. The compounds are characterized by IR and 31P NMR spectroscopic studies and by X‐ray diffraction analyses.
Tetrakis(1‐adamantylcarboxylato)dikupfer(II) Cu2(1‐Ad)4 – Synthese, Struktur und X‐/Q‐Band‐EPR‐Untersuchungen
Authors: Griebel Jan , Leistner Franziska , Krautscheid Harald , Kirmse Reinhard 
Published: March 2006

AbstractTetrakis(1‐adamantylcarboxylato)dicopper(II) Cu2(1‐Ad)4 – Synthesis, Structure and X‐/Q‐band EPR InvestigationsThe synthesis and the crystal structure of tetrakis(1‐adamantylcarboxylato)dicopper(II) are reported. [Cu2(1‐Ad)4·2DMF] (1, 1‐Ad = adamantylcarboxylate) crystallizes in the space group $P{\bar 1}$ (Z = 2) with two crystallographically distinguishable complexes in the unit cell. The averaged Cu‐Cu distance of 260.5 pm is smaller than that found for Cu2(ac)4·2H2O. The combination of temperature‐dependent X‐ and Q‐band powder EPR investigations in the temperature range 6 ≤ T ≤ 295 K show the presence of an antiferromagnetically coupled Cu‐Cu dimer and allow a precise determination of the spin‐Hamiltonian parameter. A comparison of those with that derived for Cu2(ac)4·2H2O indicate a higher symmetry within the Cu2O8 central unit of [Cu2(1‐Ad)4·2DMF].
Neue Kupferkomplexe mit Phosphaalkenliganden. Molekülstruktur von [Cu{P(Mes*)C(NMe2)2}2]BF4 (Mes* = 2,4,6‐tBu3C6H2)
Authors: Weber L. , Krümberg Jens , Stammler H.‐G. , Neumann B. 
Published: March 2006

AbstractNew Copper Complexes Containing Phosphaalkene Ligands. Molecular Structure of [Cu{P(Mes*)C(NMe2)2}2]BF4 (Mes* = 2,4,6‐tBu3C6H2)Reaction of equimolar amounts of the inversely polarized phosphaalkene tBuP=C(NMe2)2 (1a) and copper(I) bromide or copper(I) iodide, respectively, affords complexes [Cu3X3{μ‐P(tBu)C(NMe2)2}3] (2) (X =Br) and (3) (X = I) as the formal result of the cyclotrimerization of a 1:1‐adduct. Treatment of 1a with [Cu(L)Cl] (L = PiPr3; SbiPr3) leads to the formation of compounds [CuCl(L){P(tBu)C(NMe2)2}] (4a) (L = PiPr3) and (4b) (L = SbiPr3), respectively. Reaction of [(MeCN)4Cu]BF4 with two equivalents of PhP=C(NMe2)2 (1b) yields complex [Cu{P(Ph)C(NMe2)2}2]BF4 (5b). Similarly, compounds [Cu{P(Aryl)C(NMe2)2}2]BF4 (5c (Aryl = Mes and 5d (Aryl = Mes*)) are obtained from ArylP=C(NMe2)2 (1c: Aryl = Mes; 1d: Mes*) and [(MeCN)4Cu]BF4 in the presence of SbiPr3. Complexes 2, 3, 4a, 4b, and 5b‐5d are characterized by means of elemental analyses and spectroscopy (1H‐, 13C{1H}‐, 31P{1H}‐NMR). The molecular structure of 5d is determined by X‐ray diffraction analysis.
Ternary Alkali Metal Transition Metal Acetylides
Authors: Ruschewitz Uwe 
Published: March 2006

AbstractThe first alkali metal transition metal acetylides of general composition A2M0C2 (A = Na − Cs, M0 = Pd, Pt) were obtained by solid state reactions of alkali metal acetylides with palladium and platinum. They are characterized by $^{1}_{\infty}[{\rm M}^{\rm o}({\rm C}_{2})^{2-}_{{2}/{2}}]$ chains, which are separated by alkali metal ions. Analogous $^{1}_{\infty}[{\rm M}^{\rm o}({\rm C}_{2})^{2-}_{{2}/{2}}]$ chains also separated by alkali metal ions are the characteristic structural feature of acetylides of composition AMIC2, which are accessible by reacting AC2H with MII in liquid ammonia (A = Li − Cs, MI = Cu, Ag, Au). Despite their structural similarities they possess different properties, as acetylides of composition A2M0C2 are semiconductors with very small indirect band gaps and slightly extended C–C distances compared to a C–C triple bond, whereas acetylides of composition AMIC2 show a typical salt‐like behavior with C–C distances close to the expected value for a C–C triple bond of 120 pm. But with the help of simple chemical models these differences can be made plausible. Furthermore, it is shown that only by a combination of different methods (powder diffraction with X‐rays and neutrons, solid state NMR spectroscopy, Raman spectroscopy) it was possible to characterize this new class of compounds structurally and chemically.
Recurrence of brain tumours in patients treated with growth hormone: Analysis of KIGS (Pfizer International Growth Database)
Authors: Darendeliler Feyza , Karagiannis Georgios , Wilton Patrick , Ranke Michael B. , Albertsson‐Wikland Kerstin , Price David Anthony ,   On Behalf Of The Kigs International Board
Published: March 2006

Abstract Background: Growth hormone (GH) has been used successfully in the treatment of short stature secondary to GH deficiency in survivors of childhood brain tumours. There has been concern that GH might increase the risk of recurrence. Aim: To analyse KIGS (Pfizer International Growth Database) with respect to tumour recurrence in patients with brain tumours. Methods: Data for tumour recurrence were analysed retrospectively in 1038 patients with craniopharyngiomas, 655 with medulloblastomas, 113 with ependymomas, 297 with germinomas, and 400 with astrocytomas or gliomas. All patients had received recombinant human GH (Genotropin®, Pfizer Inc.). Results: Recurrence‐free survival rates were 63% at a follow‐up of 10.3 y in craniopharyngioma, 69% in 9.1 y in the glial tumours, 71% in 7.4 y in germinomas, 92% in 4.6 y in medulloblastomas and 89% in 2.5 y in ependymomas. Dose of GH and treatment modalities did not differ significantly between patients with and without recurrence. Conclusion: Tumour recurrence rates in surviving patients with brain tumours receiving GH treatment do not appear to be increased compared with published reports. However, longer follow‐up regarding recurrences and secondary neoplasms remains essential.
Cathepsin K expression is diminished in infants with bronchopulmonary dysplasia
Authors: Knaapi Jonni , Lukkarinen Heikki , Kiviranta Riku , Steiner Aida , Lassus Patrick , Andersson Sture , Kääpä Pekka 
Published: March 2006

AbstractThe expression of a potent collagenolytic enzyme, cathepsin K, was measured in repeated tracheal aspirate samples from premature infants with and without a chronic lung disorder, bronchopulmonary dysplasia (BPD). At 9–13 d, but not before, cathepsin K expression was significantly lower in the lungs of premature infants developing BPD. Conclusion: Insufficient pulmonary cathepsin K in BPD may predispose premature lungs to pulmonary fibrosis.
Gender differences in neurodevelopmental outcomes among extremely preterm, extremely‐low‐birthweight infants
Authors: Hintz Susan R. , Kendrick Douglas E. , Vohr Betty R. , Poole W. Kenneth , Higgins Rosemary D. ,   For The Nichd Neonatal Research Network
Published: March 2006

Abstract Aim: To determine whether gender‐specific responses to perinatal and neonatal events and exposures explain the male disadvantage in early childhood outcomes. Methods: Infants were in the National Institute of Child Health and Human Development (NICHD) Neonatal Research Network, born 1/1/1997–12/31/2000, <28 wk, with neurodevelopmental follow‐up at 18–22 mo corrected age. We evaluated and compared univariate and multivariate associations of risk factors with neurodevelopmental outcomes for girls and boys. Neurodevelopmental impairment (NDI) was one or more of the following: moderate–severe cerebral palsy (CP), Bayley Mental (MDI) or Psychomotor (PDI) Development Indices <70, deafness or blindness. Results: Boys (n=1216) were more likely than girls (n=1337) to have adverse outcomes (moderate–severe CP: 10.7% vs 7.3%; MDI<70: 41.9% vs 27.1%; NDI: 48.1% vs 34.1%). Major risk factors were also more common in boys. Independent multivariate associations of risk factors with outcome differed by gender, but not consistently in favor of girls. In multivariate models including both girls and boys, male gender remained an independent risk factor for MDI<70 (2.0, 95% CI 1.6–2.5) and NDI (1.8, 95% CI 1.5–2.2). Conclusion: Perinatal, neonatal and early childhood factors confer similar incremental risk or protection to boys and girls, but boys appear to have inherently greater baseline risk. Unmeasured biological variables likely contribute to the preterm male neurodevelopmental outcome disadvantage.