Chemistry of re with N,N'-bis(2-pyridylmethyl)ethylenediamine (H2pmen): hydrolysis, dehydrogenation, and ternary complexes

A number of Re complexes with N,N'-bis(2-pyridylmethyl)ethylenediamine (H2pmen) have been made from [NH4][ReO4]. [ReOCl2(H2pmen)]Cl, [ReOCl(Hpmen)][ReO4], and [ReO2(H2pmen)][ReO4] are related by hydrolysis/HCl substitution. [ReOCl(Hpmen)][ReO4] was structurally characterized and found to contain a water-stable amido-Re bond. Dehydrogenation of the N-donor ligand from each amine to imine with concomitant two-electron reduction of the Re center occurs readily in these systems. With suitable 3-hydroxy-4-pyrones, ternary complexes such as [ReIIICl(ma)(C14H14N4)][ReO4].CH3OH, 5, were made from [NH4][ReO4], H2pmen.4HCl and pyrones in one-pot syntheses. 5, a seven-coordinate ReIII complex, was structurally characterized.     

Hydrothermal vanadium fluoride chemistry: four new V3+ chain structures

An exploratory study of the hydrothermal chemistry of vanadium in HF solutions has resulted in the preparation of four new vanadium (III) fluorides with chainlike structural motifs. [NH4]2[VF5] (1) and [C2N2H10][VF5] (2) feature infinite chains of trans corner-sharing VF4F2/2 octahedra, [C4N2H6][VF5].H2O (3) has cis corner-sharing [VF4F2/2]infinity chains, and [C10N2H8][VF3] (4) has trans corner-sharing [VF2F2/2]infinity chains bridged into sheets by the 4,4'-bipy linker. All four compounds exhibit antiferromagnetic behavior.     

Influence of hydrogen bonding on the assembly of six-membered vanadium borophosphate cluster anions: synthesis and structures of (NH4)2(C2H10N2)6[Sr(H2O)5]2[V2P2BO12](6)10H2O, (NH4)2(C3H12N2)6[Sr(H2O)4]2[V2P2BO12](6)17H2O, and (NH4)3(C4H14N2)4 5[Sr(H2O)5]2[Sr(H2O)4][V2P2BO12]6 10H2O

Three new strontium vanadium borophosphate compounds, (NH4)2(C2H10N2)6[Sr(H2O)5]2[V2P2BO12]6 10H2O (Sr-VBPO1) (1), (NH4)2(C3H12N2)6[Sr(H2O)4]2[V2P2BO12]6 17H2O (Sr-VBPO2) (2), and (NH4)3(C4H14N2)4.5[Sr(H2O)5]2[Sr(H2O)4][V2P2BO12]6 10H2O (Sr-VBPO3) (3) have been synthesized by interdiffusion methods in the presence of diprotonated ethylenediamine, 1,3-diaminopropane, and 1,4-diaminobutane. Compound 1 has a chain structure, whereas 2 and 3 have layered structures with different arrangements of [(NH4) [symbol: see text] [V2P2BO12]6] cluster anions within the layers. Crystal data: (NH4)2(C2H10N2)6[Sr(H2O)5]2[V2P2BO12]6 10H2O, monoclinic, space group C2/c (no. 15), a = 21.552(1) A, b = 27.694(2) A, c = 20.552(1) A, beta = 113.650(1) degrees, Z = 4; (NH4)2(C3H12N2)6[Sr(H2O)4]2[V2P2BO12]6 17H2O, monoclinic, space group I2/m (no. 12), a = 15.7618(9) A, b = 16.4821(9) A, c = 21.112(1) A, beta = 107.473(1) degrees, Z = 2; (NH4)3(C4H14N2)4.5[Sr(H2O)5]2[Sr(H2O)4] [V2P2BO12]6 10H2O, monoclinic, space group C2/c (no. 15), a = 39.364(2) A, b = 14.0924(7) A, c = 25.342(1) A, beta = 121.259(1) degrees, Z = 4. The differences in the three structures arise from the different steric requirements of the amines that lead to different amine-cluster hydrogen bonds.     

Eta 1 and eta 2 Coordination of 1-amino-closo-dodecaborate

The reaction of the sodium salt of 1-amino-closo-dodecaborate [Na]2[NH2-B12H11] ([Na]2[1]) with [Au(PPh3)Cl] and [Ni(THF)2(Br)2] led to eta 1(N) coordination of 1in [Na][Au(PPh3)(NH2-B12H11)] (2) and [Na]6[Ni(NH2-B12H11)4] (3), respectively. Furthermore, eta 2(N,BH) coordination of was found in [MePPh3][Rh(PPh3)2(NH2-B12H11)] (4), which was synthesized by the reaction of [MePPh3][Na][1] with [Rh(PPh3)3Cl]. All compounds were characterized by single crystal X-ray diffraction and heteronuclear NMR spectroscopy.     

Facile access to redox-active C2-bridged complexes with half-sandwich manganese end groups

The dinuclear mixed-valent complex [(MeC5H4)(dmpe)MnC(2)Mn(dmpe)(C5H4Me)](+)[(eta2-MeC5H4)3Mn](-)[1](+)[2]- (dmpe=1,2-bis(dimethylphosphanyl)ethane) was prepared by the reaction of [Mn(MeC5H4)2] with dmpe and Me(3)SnC[triple chemical bond]CSnMe3. The reactions of [1](+)[2]- with K[PF6] and Na[BPh4] yielded the corresponding anion metathesis products [(MeC5H4)(dmpe)MnC2Mn(dmpe)(C5H4Me)][PF6] ([1][PF6]) and [(MeC5H4)(dmpe)MnC2Mn(dmpe)(C5H4Me)][BPh4] ([1][BPh4]). These mixed-valent species can be reduced to the neutral form by reaction with Na/Hg. The obtained complex [(MeC5H4)(dmpe)MnC2Mn(dmpe)(C5H4Me)] (1) displays a triplet/singlet spin equilibrium in solution and in the solid state, which was additionally studied by DFT calculations. The diamagnetic dicationic species [(MeC5H4)(dmpe)MnC2Mn(dmpe)(C5H4Me)][PF6]2 ([1][PF6]2) was obtained by oxidizing the mixed-valent complex [1][PF6] with one equivalent of [Fe(C5H5)2][PF6]. Both redox processes are fully reversible. The dinuclear compounds were characterized by NMR, IR, UV-visible, and Raman spectroscopy, cyclic voltammetry, and magnetic susceptibility measurements. X-ray diffraction studies were performed on [1][2], [1][PF6], [1][BPh4], and [1][PF6]2.     

Vibrational spectra of Na, K, Mn2+, Ni2+ and Zn2+ salts of 1,2,4,5-benzenetetracarboxylic (pyromellitic) acid--a short hydrogen bond evidence

Five salts of 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), [C6H2(COO)4H4], have been synthesized and investigated by infrared and Raman spectroscopy and by single crystal X-ray diffraction methods: sodium salt [Na2(H2O)2][C6H2(COO)4H2], potassium salt [K(H2O)3][C6H2(COO)4H3] and transition metal salts [M(H2O)6][C6H2(COO)4H2], which M = Mn, Ni and Zn. Crystal structures of all five compounds show short intramolecular asymmetric hydrogen bonds (SHB) between adjacent carboxyl groups with O...O distance average of 2.40 A. The Raman and infrared spectra reported indicate the presence of short hydrogen bonds in all salts, in agreement with the X-ray data. The O-H stretching mode [nu(OH)] had been observed at about 2500 cm(-1). Deuterated analogues were synthesized and their Raman spectra show that nu(OH)/nu(OD) ratio average is about unit. The symmetric [nu(sym)(O..H..O)] and asymmetric [nu(asym)(O..H..O)] stretching modes have been attributed about 300 and 870 cm(-1), respectively, in all salts, and for deuterated analogues, the ratio nu(OH)/nu(OD) to nu(sym)(O..H..O, O..D..O) is close to unit like it occurs in nu(OH). The vibrational modes, mainly SHB modes, are tentatively assigned by molecular orbital ab initio calculations of pyromellitic acid and anions [C6H2(COO)4H3]- and [C6H2(COO)4H2]2-. Geometry optimizations showed a good agreement with experimental data. Frequency calculation confirms the assignment of specific vibrational modes. Ab initio calculations show that nu(C=O) and nu(sym)(COO) are strongly coupled with in plane OH bending [delta(OH)]. In Raman spectra of deuterated analogues is observed a frequency shift of these bands.     

Synthesis and characterization of six-coordinate "3 + 2" mixed-ligand oxorhenium complexes with the o-diphenylphosphinophenolato ligand and tridentate coligands of different N and S donor atom combinations

A series of octahedral six-coordinate oxorhenium(V) mixed ligand complexes containing the common [ReO(L)]2+ fragment (L = o-OC6H4P(C6H5)2] have been synthesized and characterized. Hence, it was shown that the [ReO(L)]2+ moiety can accommodate a variety of tridentate ligands containing a central amine group amenable to deprotonation and different combinations of lateral groups, such as ethylamine, substituted ethylamine, ethylthiol, and ethylthioether arms. In particular, by reaction of equimolar amounts of the pertinent HLn ligands with the [(n-C4H9)4N][ReOCl3(L)] precursor in refluxing acetonitrile/methanol or dichloromethane/methanol mixtures, the following series of [ReO(Ln)(L)]+/0 oxorhenium(V) complexes has been generated: ReO[[N(CH2CH2NH2)2][o-OC6H4P(C6H5)2]]Cl (1); ReO[[C2H5)2NCH2CH2NCH2CH2S][o-OC6H4P5)2]] (2); ReO[[(CH2)4NCH2CH2NCH2CH2S][o-OC6H4P(C6H4P(C6H5)2]] (3); and ReO[[C2H5SCH2CH2NCH2CH2S][o-OC6H4P(C6H5)2]] (4). The complexes are closed-shell 18-electron oxorhenium species, which adopt octahedral geometries both in solution and in the solid state, as established by conventional physicochemical techniques including multinuclear NMR and single-crystal X-ray diffraction analyses.     

Amino-closo-dodecaborate--a new ligand in coordination chemistry

The synthesis and characterization of three ruthenium complexes [Bu(3)MeN][Ru(PPh(3))(2)(NH(2)-B(12)H(11))Cl], [Bu(4)N][Ru(dppb)(NH(2)-B(12)H(11))Cl] and [RuCO(PPh(3))(2)(NH(2)-B(12)H(11))] with amino-closo-dodecaborate as the coordinating ligand are described.     

1-H2N-CB11F11]---synthesis and reactions of a functionalized fluorinated carbadodecaborate anion

In anhydrous hydrogen fluoride, K[1-H2N-CB11H11] is fluorinated with elemental fluorine to produce K[1-H2N-CB11F11]. Under strong alkaline conditions, two fluorine atoms of the [1-H2N-CB11F11]- anion are regioselectively exchanged, yielding the [1-H2N-4,6-(HO)2-CB11F9]- anion via [1-H2N-6-HO-CB11F10]- as an intermediate. Both hydroxycarborate anions were isolated as [Ph4P]+ salts. All of the species were characterized by IR, Raman, and multi-NMR spectroscopy, thermal analysis (DSC) as well as by mass spectrometry (MALDI). The assignment of the NMR signals was supported by DFT calculations. Solid-state structures of K[1-H2N-CB11F11], [BzPh3P][1-H2N-CB11F11], [Ph4P][1-H2N-4,6-(HO)2-CB11F9], [Ph4P][1-H2N-6-HO-CB11F10], and [BzPh3P][1-H2N-CB11H11] were determined by single-crystal X-ray diffraction.     

Copper-linked hexaniobate lindqvist clusters-variations on a theme

Four new one-dimensional materials and one dimer complex based on the linkage of [Nb6O19] clusters and [CuLx] (L=ethylenediamine (en), NH3, H2O) assemble under ambient conditions. These phases include the following: Rb4[Cu(en)2(H2O)2]3[(Nb6O19H2)2Cu(en)2].24H2O (1), space group P; [Cu(en)2(H2O)2]2[(Nb6O19H2)Cu(en)2].14H2O (2), space group P; Rb2[Cu(NH3)2(H2O)4][Cu(NH3)4(H2O)2]2{[Nb6O19][Cu(NH3)]2}(2).6H2O (3), space group P; {[Nb6O19][Cu(NH3)2(H2O)]2[Cu(H2O)4]2}.3H2O (4), space group P2/n; and {[Nb6O19][Cu(NH3)2(H2O)]2[Cu(H2O)4]2} (5), space group C2/m. All structures have been solved by single-crystal methods, and compounds 1-5 were characterized by thermogravimetric analysis, Fourier transform IR, chemical analysis, and magnetic measurements. It has been demonstrated that the conformation, charge, and geometry of the [Nb6O19]-[CuLx] chains can be modulated by varying the type and amount of the [CuLx]2+ species. The charge balance is provided by mixed Rb+/[CuLx]2+ or [CuLx]2+ cations only for structures 1-3, whereas 4 and 5 are neutral chains with no counterions. There are weak antiferromagnetic Cu2+-Cu2+ interactions in all phases. Compounds 2-5 represent the first examples in which the [Nb6O19] Lindqvist ion forms extended solids rather than dimers or decorated monomers when reacted with transition-metal, cationic complexes.     

First characterization of the ammine-ammonium complex [(NH4(NH3)4)2(mu-NH3)2]2+ in the crystal structure of [NH4(NH3)4][B(C6H5)4].NH3 and the [NH4(NH3)4]+ complex in [NH4(NH3)4][Ca(NH3)7]As3S6.2NH3 and [NH4(NH3)4][Ba(NH3)8]As3S6.NH3

The compound [NH4(NH3)4][B(C6H5)4].NH3 (1) was prepared by the reaction of NaB(C(6)H(5))(4) with a proton-charged ion-exchange resin in liquid ammonia. [NH(4)(NH(3))(4)][Ca(NH(3))(7)]As(3)S(6).2NH(3) (2) and [NH4(NH3)4][Ba(NH3)8]As3S6.NH3 (3) were synthesized by reduction of As(4)S(4) with Ca and Ba in liquid ammonia. All ammoniates were characterized by low-temperature single-crystal X-ray structure analysis. They were found to contain the ammine-ammonium complex with the maximal possible number of coordinating ammonia molecules, the [NH4(NH3)4]+ ion. 1 contains a special dimer, the [(NH4(NH3)4)2(mu-NH3)2]2+ ion, which is formed by two[NH4(NH3)4]+ ions linked by two ammonia molecules. The H(3)N-H...N hydrogen bonds in all three compounds range from 1.82 to 2.20 A (DHA = Donor-H...Acceptor angles: 156-178 degrees). In 2 and 3, additional H(2)N-H...S bonds to the thioanions are observed, ranging between 2.49 and 3.00 A (DHA angles: 120-175 degrees). Two parallel phenyl rings of the [B(C(6)H(5))(4)](-) anion in 1 form a pi...pi hydrogen bond (C...C distance, 3.38 A; DHA angles, 82 degrees), leading to a dimeric [B(C6H5)4]2(2-) ion.     

Syntheses of [F5TeNH3][AsF6], [F5TeN(H)Xe][AsF6], and F5TeNF2 and characterization by multi-NMR and Raman spectroscopy and by electronic structure calculations: the X-ray crystal structures of alpha- and beta-F5TeNH2, [F5TeNH3][AsF6], and [F5TeN(H)Xe][AsF6

The salt, [F5TeN(H)Xe][AsF6], has been synthesized in the natural abundance and 99.5% 15N-enriched forms. The F5TeN(H)Xe+ cation has been obtained as the product of the reactions of [F5TeNH3][AsF6] with XeF2 (HF and BrF5 solvents) and F5TeNH2 with [XeF][AsF6] (HF solvent) and characterized in solution by 129Xe, 19F, 125Te, 1H, and 15N NMR spectroscopy at -60 to -30 degrees C. The orange [F5TeN(H)Xe][AsF6] and colorless [F5TeNH3][AsF6] salts were crystallized as a mixture from HF solvent at -35 degrees C and were characterized by Raman spectroscopy at -165 degrees C and by X-ray crystallography. The crystal structure of the low-temperature phase, alpha-F5TeNH2, was obtained by crystallization from liquid SO2 between -50 and -70 degrees C and is fully ordered. The high-temperature phase, beta-F5TeNH2, was obtained by sublimation at room temperature and exhibits a 6-fold disorder. Decomposition of [F5TeN(H)Xe][AsF6] in the solid state was rapid above -30 degrees C. The decomposition of F5TeN(H)Xe+ in HF and BrF5 solution at -33 degrees C proceeded by fluorination at nitrogen to give F5TeNF2 and Xe gas. Electronic structure calculations at the Hartree-Fock and local density-functional theory levels were used to calculate the gas-phase geometries, charges, Mayer bond orders, and Mayer valencies of F5TeNH2, F5TeNH3+, F5TeN(H)Xe+, [F5TeN(H)Xe][AsF6], F5TeNF2, and F5TeN2- and to assign their experimental vibrational frequencies. The F5TeN(H)Xe+ and the ion pair, [F5TeN(H)Xe][AsF6], systems were also calculated at the MP2 and gradient-corrected (B3LYP) levels.     

Protonation of a lanthanum phosphide-alkyl occurs at the P-La not the C-La bond: isolation of a cationic lanthanum alkyl complex

Protonation of the heteroleptic, cyclometalated lanthanum phosphide complex [((Me3Si)2CH)(C6H4-2-CH2NMe2)P]La(THF)[P(C6H4-2-CH2NMe2)(CH(SiMe3)(SiMe2CH2))] with [Et3NH][BPh4] yields the cationic alkyllanthanum complex [(THF)4La[P(C6H4-2-CH2NMe2)(CH(SiMe3)(SiMe2CH2))]][BPh4].     

Simple preparations of Pd6Cl12, Pt6Cl12, and Qn[Pt2Cl8+n], n=1, 2 (Q=TBA+, PPN+) and structural characterization of [TBA][Pt2Cl9] and [PPN]2[Pt2Cl10].C7H8

The hexanuclear Pd6Cl12, i.e., the crystal phase classified as beta-PdCl2, was obtained by reacting [TBA]2[Pd2Cl6] with AlCl3 (or FeCl3) in CH2Cl2. The action of AlCl3 on PtCl42-, followed by digestion of the resulting solid in 1,2-C2H4Cl2 (DCE), CHCl3, or benzene, produced Pt6Cl12.DCE, Pt6Cl12.CHCl3, or Pt6Cl12.C6H6, respectively. Treating [TBA]2[PtCl6] with a slight excess of AlCl3 afforded [TBA][Pt2Cl9], whose anion was established crystallographically to be constituted by two "PtCl6" octahedra sharing a face. Dehydration of H2PtCl6.nH2O with SOCl2 gave an amorphous compound closely analyzing as PtCl4, reactive with [Q]Cl in SOCl2 to yield [Q][Pt2Cl9] or [Q]2[Pt2Cl10], depending on the [Q]Cl/Pt molar ratio (Q=TBA+, PPN+). A single-crystal X-ray diffraction study has shown [PPN]2[Pt2Cl10].C7H8 to contain dinuclear anions formed by two edge-sharing PtCl6 octahedra.     

Ytterbium and samarium bis(diphosphanylamides): syntheses and structures of lanthanide complexes having two [(Ph2P)2N]- ligands in the coordination sphere

Bis(diphosphanylamide) complexes of the lanthanides have been synthesized. Two approaches to obtain these compounds are shown. Reaction of YbCl3 with a slight excess of [K(THF)n][N(PPh2)2] gives [((Ph2P)2N)2 YbCl(THF)2], which can be further reacted with K(C5Me5) to give the corresponding pentamethylcyclopentadienyl complex [((Ph2P)2N)2Yb(C5Me5)]. In a second approach to bis(diphosphanylamide) complexes of the lanthanides, Na(C(5)H(5)) was treated with SmCl3 to generate [(C5H5)SmCl2(THF)3] in situ. Further reaction with 2 equiv of [K(THF)n][N(PPh2)2] gave the desired complex [((Ph2P)2N)2Sm(C5H5)(THF)].     

Octahedral Ru(II) amido complexes TpRu(L)(L')(NHR) (Tp = hydridotris(pyrazolyl)borate; L = L' = P(OMe)3 or PMe3 or L = CO and L' = PPh3; R = H,Ph, or tBu): synthesis,characterization, and reactions with weakly acidic C-H bonds

The octahedral Ru(II) amine complexes [TpRu(L)(L')(NH(2)R)][OTf] (L = L' = PMe(3), P(OMe)(3) or L = CO and L' = PPh(3); R = H or (t)Bu) have been synthesized and characterized. Deprotonation of the amine complexes [TpRu(L)(L')(NH(3))][OTf] or [TpRu(PMe(3))(2)(NH(2)(t)Bu)][OTf] yields the Ru(II) amido complexes TpRu(L)(L')(NH(2)) and TpRu(PMe(3))(2)(NH(t)Bu). Reactions of the parent amido complexes or TpRu(PMe(3))(2)(NH(t)Bu) with phenylacetylene at room temperature result in immediate deprotonation to form ruthenium-amine/phenylacetylide ion pairs, and heating a benzene solution of the [TpRu(PMe(3))(2)(NH(2)(t)Bu)][PhC(2)] ion pair results in the formation of the Ru(II) phenylacetylide complex TpRu(PMe(3))(2)(C[triple bond]CPh) in >90% yield. The observation that [TpRu(PMe(3))(2)(NH(2)(t)Bu)][PhC(2)] converts to the Ru(II) acetylide with good yield while heating the ion pairs [TpRu(L)(L')(NH(3))][PhC(2)] yields multiple products is attributed to reluctant dissociation of ammonia compared with the (t)butylamine ligand (i.e., different rates for acetylide/amine exchange). These results are consistent with ligand exchange reactions of Ru(II) amine complexes [TpRu(PMe(3))(2)(NH(2)R)][OTf] (R = H or (t)Bu) with acetonitrile. The previously reported phenyl amido complexes TpRuL(2)(NHPh) [L = PMe(3) or P(OMe)(3)] react with 10 equiv of phenylacetylene at elevated temperature to produce Ru(II) acetylide complexes TpRuL(2)(C[triple bond]CPh) in quantitative yields. Kinetic studies indicate that the reaction of TpRu(PMe(3))(2)(NHPh) with phenylacetylene occurs via a pathway that involves TpRu(PMe(3))(2)(OTf) or [TpRu(PMe(3))(2)(NH(2)Ph)][OTf] as catalyst. Reactions of 1,4-cyclohexadiene with the Ru(II) amido complexes TpRu(L)(L')(NH(2)) (L = L' = PMe(3) or L = CO and L' = PPh(3)) or TpRu(PMe(3))(2)(NH(t)Bu) at elevated temperatures result in the formation of benzene and Ru hydride complexes. TpRu(PMe(3))(2)(H), [Tp(PMe(3))(2)Ru[double bond]C[double bond]C(H)Ph][OTf], [Tp(PMe(3))(2)Ru=C(CH(2)Ph)[N(H)Ph]][OTf], and [TpRu(PMe(3))(3)][OTf] have been independently prepared and characterized. Results from solid-state X-ray diffraction studies of the complexes [TpRu(CO)(PPh(3))(NH(3))][OTf], [TpRu(PMe(3))(2)(NH(3))][OTf], and TpRu(CO)(PPh(3))(C[triple bond]CPh) are reported.     

Diazo complexes of rhenium: preparations and crystal structures of the bis(dinitrogen), [Re(N2)2(PPh(OEt)2)4][BPh4] and methyldiazenido [ReCl(CH3N2)(CH3NHNH2)(PPh(OEt)2)3][BPh4] derivatives

Depending on experimental conditions and the nature of the hydrazine, the reactions of ReCl3P3 [P = PPh(OEt)2] with RNHNH2 (R = H, CH3, tBu) afford the bis(dinitrogen) [Re(N2)2P4]+ (2+), dinitrogen ReClN2P4 (3), and methyldiazenido [ReCl(CH3N2)(CH3NHNH2)P3]+ (1+) derivatives. In contrast, reactions of ReCl3P3 [P = PPh(OEt)2, PPh2OEt] with arylhydrazines ArNHNH2 (Ar = Ph, p-tolyl) give the aryldiazenido cations [ReCl(ArN2)(ArNHNH2)P3]+ (4+) and [ReCl(ArN2)P4]+ (7+) and the bis(aryldiazenido) cations [Re(ArN2)2P3]+ (5+, 6+). These complexes were characterized spectroscopically (IR; 1H and 31P NMR), and the BPh4 complexes 1, 2, and 7 were characterized crystallographically. The methyldiazenido derivative [ReCl(CH3N2)(CH3NHNH2)(PPh(OEt)2)3][BPh4] (1) crystallizes in space group P1 with a = 15.396(5) A, b = 16.986(5) A, c = 11.560(5) A, alpha = 93.96(5) degrees, beta = 93.99(5) degrees, gamma = 93.09(5) degrees, and Z = 2 and contains a singly bent CH3N2, group bonded to an octahedral central metal. One methylhydrazine ligand, one Cl- trans to the CH3N2, and three PPh(OEt)2 ligands complete the coordination. The complex [Re(N2)2(PPh(OEt)2)4][BPh4] (2) crystallizes in space group Pbaa with a = 23.008(5) A, b = 23.367(5) A, c = 12.863(3) A, and Z = 4. The structure displays octahedral coordination with two end-on N2 ligands in mutually trans positions. [ReCl(PhN2)(PPh(OEt)2)4][BPh4] (7) crystallizes in space group P2(1)/n with a = 19.613(5) A, b = 20.101(5) A, c = 19.918(5) A, beta = 115.12(2) degrees, and Z = 4. The structure shows a singly bent phenyldiazenido group trans to the Cl- ligand in an octahedral environment. The dinitrogen complex ReClN2P4 (3) reacts with CF3SO3CH3 to give the unstable methyldiazenido derivative [ReCl(CH3N2)P4][BPh4]. Reaction of the methylhydrazine complex [ReCl(CH3N2)(CH3NHNH2)P3][BPh4] (1) with Pb(OAc)4 at -30 degrees C results in selective oxidation of the hydrazine, affording the corresponding methyldiazene derivative [ReCl(CH3N=NH)(CH3N2)P3][BPh4] (8). In contrast, treatment with Pb(OAc)4 of the related arylhydrazines [ReCl(ArN2)(ArNHNH2)P3][BPh4] (4) [P = PPh(OEt)2] gives the bis(aryldiazenido) complexes [Re(ArN2)2P3][BPh4] (5). Possible protonation reactions of Br?nsted acids HX with all diazenides, 1, 4, 5, 6, and 8, were investigated and found to proceed only in the cases of the bis(aryldiazenido) complexes 5 and 6, affording, with HCl, the octahedral [ReCl(ArN=NH)(ArN2)P3][BPh4] or [ReCl(Ar(H)NN)(ArN2)P3][BPh4] (10) (Ar = Ph; P = PPh2OEt) derivative.     

COMPLEX SALTS [Pd(NH3)4][Pd(NH3)3NO2] [CrOx3]·H2O AND [Pd(NH3)4][Pd(NH3)3NO2] [CoOx3]·H2O AND SOLID SOLUTIONS [Pd(NH3)4] [Pd(NH3)3NO2][CoOx3]x[RhOx3]1–x·H2O : PROMISING PRECURSORS FOR POROUS NANOALLOYS

Journal of Structural Chemistry - New complex salts [Pd(NH3)4][Pd(NH3)3NO2][CrOx3]·H2O I, [Pd(NH3)4][Pd(NH3)3NO2][CoOx3]·H2O II, and a series of solid solutions...     

Solution and solid-state preparation of 18-crown[6] complexes with M[HSO4]n salts (M = NH4+, K+, Sr2+ and n = 1, 2) and an investigation of solvation/desolvation processes and crystal polymorphism

18-Crown[6] ether has been used to prepare a new class of organic-inorganic complexes of general formula 18-crown[6]M[HSO(4)](n) (where M = NH(4) (+), K(+), Sr(2+) and n = 1, 2) by reacting directly in solution or in the solid state the crown ether 18-crown[6] with inorganic salts such as [NH(4)][HSO(4)], K[HSO(4)], and Sr[HSO(4)](2). The structures of 18-crown[6][NH(4)][HSO(4)]2 H(2)O (12 H(2)O), 18-crown[6][NH(4)][HSO(4)] (1), 18-crown[6]K[HSO(4)]2 H(2)O (22 H(2)O), 18-crown[6]K[HSO(4)] (2), and 18-crown[6]Sr[HSO(4)](2) (3) have been characterized by single-crystal X-ray diffraction. The reversible water loss in compounds 12 H(2)O and 22 H(2)O leads to formation of the corresponding anhydrous phases 18-crown[6][NH(4)][HSO(4)] (1), and 18-crown[6]K[HSO(4)] (2), which undergo, on further heating, enantiotropic solid-solid transitions very likely associated with the on-set of a solid state dynamical process. Similar high-temperature behavior is shown by 18-crown[6]Sr[HSO(4)](2) (3). The dehydration and phase-transition processes have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and variable temperature X-ray powder diffraction.     

Cation and anion diversity in [M(dithiooxalate)2]2- salts: structure robustness in crystal synthesis

A series of crystalline salts based on the [M(dto)2]2- (dto = 1,2-dithiooxalate, M = Ni, Pt, Cu) dianion with hydrogen-bond donor cations have been synthesised following a molecular tectonics approach. The chelating M(dto)[dot dot dot]HN supramolecular synthon has been exploited in a systematic study of its robustness. The effects of competition between hydrogen-bond acceptors, of the shape and functionality of the cations and of varying the metal in the anion are discussed. The preparation and structural characterisation of the new crystalline phases [4,4'-H(2)bipy][Pt(dto)2] (2), [HNC5H4CO2H-4]2[Pt(dto)2] (5), [HNC5H4CO2H-3]2[Pt(dto)2] (6), [HNC5H4CH2CO2H-4]2[Ni(dto)2] (7), [HNC(5)H(4)CH(2)CO(2)H-3]2[Ni(dto)2] (8), [HNC5H4CONH2-4]2[Ni(dto)2] (9), [HNC5H4CHNOH-4]2[Ni(dto)2] (10), [HNC5H4CHNOH-3]2[Ni(dto)2] (11), [4,4'-H2bipip][Ni(dto)2] (12), [H2NC5H9CO2H-4]2[Pt(dto)2] (12), [H2NC5H9CO2H-4]2[Cu(dto)2] (14), [H2NC5H9CO2H-3]2[Ni(dto)2][H2O]2 (15), [H2NC5H9CO2H-3]2[Pt(dto)2][H2O]2 (16), [H2NC5H9CO2H-3]2[Cu(dto)2][H2O]2 (17), [H(Me)NC5H9CO2H-4]2[Ni(dto)2][H2O]2 (18) is reported. The charge-assisted NH[dot dot dot]dto synthon is formed in each of compounds 1-20, and is apparently much more robust than the conventional synthons used (such as the carboxylic acid dimer), which have a much lower rate of occurrence. The NH[dot dot dot]dto synthon may be generalised to 3- and 4-pyridinium species and 3- and 4-piperidinium derivatives. In the latter cases branching of the hydrogen-bond networks through the NH2 groups arises. The robustness of the NH...dto synthon allows structures of the form [NH cation]2[M(dto)2] to be regarded as being formed by the packing of neutral supermolecules. Cases of isomorphism (as in 16-18) and latent polymorphism (e.g. in 4 and 6) are noted.