Synthesis,crystal structure,and electrochemistry of [Co{(Me-sal)2dien}(N3)] and [Co{(Me-sal)2dpt}(N3)]

The structure, spectroscopic, and electrochemical properties of [Co{(Me-sal)₂dien}(N₃)] and [Co{(Me-sal)₂dpt}(N₃)], where (Me-sal)₂dien = 2,2′-[1,1′-(3-azapentane-1,5-diyldinitrilo)diethylidyne] diphenolate and (Me-sal)₂dpt = 2,2′-[1,1′-(4-azapentane-1,7-diyldinitrilo)diethylidyne] diphenolate, have been investigated. These complexes have been characterized by elemental analyses, IR, UV–Vis, and ¹H-NMR spectroscopy. The crystal structures of these complexes have been determined by X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1, with a = 7.8443(4) Å, b = 11.0660(5) Å, c = 11.6216(6) Å, α = 73.360(1)°, β = 76.965(1)°, γ = 84.436(1)° and Z = 2. Complex 2 crystallizes in the monoclinic space group P2₁/n, with a = 12.1985(13) Å, b = 10.9332(12) Å, c = 15.2808(16) Å, β = 76.965(1)° and Z = 4. The coordination geometry around cobalt(III) in both complexes is a distorted octahedron. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile indicates that the first reduction corresponding to Co^III–Co^II is electrochemically irreversible, accompanied by dissociation of the axial Co–N(N₃) bond. The second reduction step of Co(II/I) leads to decomposition of the complex. These observations are rationalized based on the structure-function relations.     

Metal(II) hexafluorophosphates(V) (M = Sr, Pb) containing XeF(2)-coordinated metal ions [M(XeF(2))(3)](PF(6))(2), [Pb(3)(XeF(2))(11)](PF(6))(6), and [Sr(3)(XeF(2))(10)](PF(6))(6)

From the system MF(2)/PF(5)/XeF(2)/anhydrous hydrogen fluoride (aHF), four compounds [Sr(XeF(2))(3)](PF(6))(2), [Pb(XeF(2))(3)](PF(6))(2), [Sr(3)(XeF(2))(10)](PF(6))(6), and [Pb(3)(XeF(2))(11)](PF(6))(6) were isolated and characterized by Raman spectroscopy and X-ray single-crystal diffraction. The [M(XeF(2))(3)](PF(6))(2) (M = Sr, Pb) compounds are isostructural with the previously reported [Sr(XeF(2))(3)](AsF(6))(2). The structure of [Sr(3)(XeF(2))(10)](PF(6))(6) (space group C2/c; a = 11.778(6) Angstrom, b = 12.497(6) Angstrom, c = 34.60(2) Angstrom, beta = 95.574(4) degrees, V = 5069(4) Angstrom(3), Z = 4) contains two crystallographically independent metal centers with a coordination number of 10 and rather unusual coordination spheres in the shape of tetracapped trigonal prisms. The bridging XeF(2) molecules and one bridging PF(6)- anion, which connect the metal centers, form complicated 3D structures. The structure of [Pb(3)(XeF(2))(11)](PF(6))(6) (space group C2/m; a = 13.01(3) Angstrom, b = 11.437(4) Angstrom, c = 18.487(7) Angstrom, beta = 104.374(9) degrees, V = 2665(6) Angstrom(3), Z = 2) consists of a 3D network of the general formula {[Pb(3)(XeF(2))(10)](PF(6))(6)}n and a noncoordinated XeF(2) molecule fixed in the crystal structure only by weak electrostatic interactions. This structure also contains two crystallographically independent Pb atoms. One of them possesses a unique homoleptic environment built up by eight F atoms from eight XeF(2) molecules in the shape of a cube, whereas the second Pb atom with a coordination number of 9 adopts the shape of a tricapped trigonal prism common for lead compounds. [Pb(3)(XeF(2))(11)](PF(6))(6) and [Sr(3)(XeF(2))(10)](PF(6))(6) are formed when an excess of XeF(2) is used during the process of the crystallization of [M(XeF(2))(3)](PF(6))(2) from their aHF solutions.     

Darstellung,Strukturen und EPR-Spektren der Rhenium(II)-Nitrosylkomplexe [Re(NO)Cl2(PPh3)(OPPh3)(OReO3)], [Re(NO)Cl2(OPPh3)2(OReO3)] und [Re(NO)Cl2(OPPh3)3](ReO4)

Synthesis, Structures, and EPR-Spectra of the Rhenium(II) Nitrosyl Complexes [Re(NO)Cl₂(PPh₃)(OPPh₃)(OReO₃)], [Re(NO)Cl₂(OPPh₃)₂(OReO₃)], and [Re(NO)Cl₂(OPPh₃)₃](ReO₄) The paramagnetic rhenium(II) nitrosyl complexes [Re(NO)Cl₂(PPh₃)(OPPh₃)(OReO₃)], [Re(NO)Cl₂(OPPh₃)₂ · (OReO₃)], and [Re(NO)Cl₂(OPPh₃)₃](ReO₄) are formed during the reaction of [ReOCl₃(PPh₃)₂] with NO gas in CH₂Cl₂/EtOH. These and two other Re^II complexes with 5 d⁵ ”︁low-spin”︁”︁-configuration can be observed during the reaction EPR spectroscopically. Crystal structure analysis shows linear coordinated NO ligands (Re–N–O-angles between 171.9 and 177.3°). Three OPPh₃ ligands are meridionally coordinated in the final product of the reaction, [Re(NO)Cl₂(OPPh₃)₃][ReO₄] (monoclinic, P2₁/c, a = 13.47(1), b = 17.56(1), c = 24.69(2) Å, β = 95.12(4)°, Z = 4). [Re(NO)Cl₂(PPh₃)(OPPh₃)(OReO₃)] (triclinic P 1, a = 10.561(6), b = 11.770(4), c = 18.483(8) Å, α = 77.29(3), β = 73.53(3), γ = 64.70(4)°, Z = 2) and [Re(NO)Cl₂ (OPPh₃)₂(OReO₃)] (monoclinic P2₁/c, a = 10.652(1), b = 31.638(4), c = 11.886(1) Å, β = 115.59(1)°), Z = 4) can be isolated at shorter reaction times besides the complexes [Re(NO)Cl₃(Ph₃P)₂], [Re(NO)Cl₃(Ph₃P) · (Ph₃PO)], and [ReCl₄(Ph₃P)₂].     

Structural characterization of Pu[N(SiMe(3))(2)](3), a synthetically useful nonaqueous plutonium(III) precursor

A rare, and synthetically versatile, nonaqueous plutonium complex, Pu[N(SiMe3)2]3 (1), has been structurally characterized by single-crystal X-ray diffraction for the first time and reveals significantly shorter agostic interactions compared to the cerium(III) analogue, indicating possible covalency differences.     

The Stereochemical Activity of the Lone Pair in [Bi(NO3)3{(iPrO)2(O)PCH2P(O)(OiPr)2}2] — Comparison of Bismuth,Lanthanum and Praseodymium Nitrate Complexes

Five coordination compounds of bismuth, lanthanum and praseodymium nitrate with the oxygen‐coordinating chelate ligand (ⁱPrO)₂(O)PCH₂P(O)(OⁱPr)₂ (L) are reported: [Bi(NO₃)₃(L)₂] ( 1 ), [La(NO₃)₃(L)₂] ( 2 ), [Pr(NO₃)₃(L)₂] ( 3 ), [La(NO₃)₃(L)(H₂O)] ( 4 ) and [Pr(NO₃)₃(L)(H₂O)] ( 5 ). The compounds were characterized by means of single crystal X‐ray crystallography, ¹H and ³¹P NMR spectroscopy in solution, solid‐state ³¹P NMR spectroscopy, IR spectroscopy, DTA‐TG measurements ( 1 , 2 and 4 ), conductometry and electrospray ionization mass spectrometry (ESI‐MS). In addition, DFT calculations for model compounds of 1 and 2 support our experimental work. In the solid state mononuclear coordination compounds were observed for 1 — 3 , whereas compounds 4 and 5 gave one‐dimensional hydrogen‐bonded polymers via water‐nitrate coordination. Despite of the similar ionic radii of bismuth(III), lanthanum(III) and praseodymium(III) for a given coordination number the bismuth and lanthanide compounds 1 — 3 are not isostructural. The bismuth compound 1 shows a 9‐coordinate bismuth atom whereas lanthanum(III) and praseodymium(III) atoms are 10‐coordinate in the lanthanide complexes 2 — 5 . The general LnO₁₀ coordination motif in compounds 2 — 5 is best described as a distorted bi‐capped square antiprism. The BiO₉ polyhedron might be deduced from the LnO₁₀ polyhedron by replacing one oxygen ligand with a stereochemically active lone pair. The one‐to‐one complexes 4 and 5 dissociate in solution to give the corresponding one‐to‐two complexes 2 and 3 , respectively, and solvated Ln(NO₃)₃. In contrast to the lanthanides, the one‐to‐two bismuth complex 1 is less stable in CH₃CN solution and partially dissociates to give solvated Bi(NO₃)₃ and (ⁱPrO)₂(O)PCH₂P(O)(OⁱPr)₂.     

Mixed-metal uranium(VI) iodates: hydrothermal syntheses,structures, and reactivity of Rb[UO(2)(CrO(4))(IO(3))(H(2)O)], A(2)[UO(2)(CrO(4))(IO(3))(2)] (A = K,Rb, Cs), and K(2)[UO(2)(MoO(4))(IO(3))(2)

The reactions of the molecular transition metal iodates A[CrO(3)(IO(3))] (A = K, Rb, Cs) with UO(3) under mild hydrothermal conditions provide access to four new, one-dimensional, uranyl chromatoiodates, Rb[UO(2)(CrO(4))(IO(3))(H(2)O)] (1) and A(2)[UO(2)(CrO(4))(IO(3))(2)] (A = K (2), Rb (3), Cs (4)). Under basic conditions, MoO(3), UO(3), and KIO(4) can be reacted to form K(2)[UO(2)(MoO(4))(IO(3))(2)] (5), which is isostructural with 2 and 3. The structure of 1 consists of one-dimensional[UO(2)(CrO(4))(IO(3))(H(2)O)](-) ribbons that contain uranyl moieties bound by bridging chromate and iodate anions as well as a terminal water molecule to create [UO(7)] pentagonal bipyramidal environments around the U(VI) centers. These ribbons are separated from one another by Rb(+) cations. When the iodate content is increased in the hydrothermal reactions, the terminal water molecule is replaced by a monodentate iodate anion to yield 2-4. These ribbons can be further modified by replacing tetrahedral chromate anions with MoO(4)(2)(-) anions to yield isostructural, one-dimensional [UO(2)(MoO(4))(IO(3))(2)](2)(-) ribbons. Crystallographic data: 1, triclinic, space group P(-)1, a = 7.3133(5) A, b = 8.0561(6) A, c = 8.4870(6) A, alpha = 88.740(1) degrees, beta = 87.075(1) degrees, gamma = 71.672(1) degrees, Z = 2; 2, monoclinic, space group P2(1)/c, a = 11.1337(5) A, b = 7.2884(4) A, c = 15.5661(7) A, beta = 107.977(1) degrees, Z = 4; 3, monoclinic, space group P2(1)/c, a = 11.3463(6) A, b = 7.3263(4) A, c = 15.9332(8) A, beta = 108.173(1) degrees, Z = 4; 4, monoclinic, space group P2(1)/n, a = 7.3929(5) A, b = 8.1346(6) A, c = 22.126(2) A, beta = 90.647(1) degrees, Z = 4; 5, monoclinic, space group P2(1)/c, a = 11.3717(6) A, b = 7.2903(4) A, c = 15.7122(8) A, beta = 108.167(1) degrees, Z = 4.     

Alkaline Earth Diazapentadienyl Compounds: Structure of [Ba2{(C6H11)NC(Me)CHC(Me)N(C6H11)}3{(SiMe3)2N}]

Three different bonding modes in one molecule! The diazapentadienyl ligands in the title compound 1 adopt η¹,η¹-N,N-chelating plus η⁵-terminal, η¹η¹-N,N chelating plus η⁵-bridging, and novel η¹-N plus η³-1-aza-allyl bonding modes. R=cyclohexyl.     

Synthesis and characterization of the SO(2)N(3)(-), (SO(2))(2)N(3)(-), and SO(3)N(3)(-) anions

SO(2) solutions of azide anions are bright yellow, and their Raman spectra indicate the presence of covalently bound azide. Removal of the solvent at -64 degrees C from CsN(3) or N(CH(3))(4)N(3) solutions produces yellow (SO(2))(2)N(3)(-) salts. Above -64 degrees C, these salts lose 1 mol of SO(2), resulting in white SO(2)N(3)(-) salts that are marginally stable at room temperature and thermally decompose to the corresponding azides and SO(2). These anions were characterized by vibrational and (14)N NMR spectroscopy and theoretical calculations. Slow loss of the solvent by diffusion through the walls of a sealed Teflon tube containing a sample of CsSO(2)N(3) in SO(2) resulted in white and yellowish single crystals that were identified by X-ray diffraction as CsSO(2)N(3).CsSO(3)N(3) with a = 9.542(2) A, b = 6.2189(14) A, c = 10.342(2) A, and beta = 114.958(4) degrees in the monoclinic space group P2(1)/m, Z = 2, and Cs(2)S(2)O(5).Cs(2)S(2)O(7).SO(2), respectively. Pure CsSO(3)N(3) was also prepared and characterized by vibrational spectroscopy. The S-N bond in SO(2)N(3)(-) is much weaker than that in SO(3)N(3)(-), resulting in decreased thermal stability, an increase in the S-N bond distance by 0.23 A, and an increased tendency to undergo rotational disorder. This marked difference is due to SO(3) being a much stronger Lewis acid (pF(-) value of 7.83) than SO(2) (pF(-) value of 3.99), thus forming a stronger S-N bond with the Lewis base N(3)(-). The geometry of the free gaseous SO(2)N(3)(-) anion was calculated at the RHF, MP2, B3LYP, and CCSD(T) levels. The results show that only the correlated methods correctly reproduce the experimentally observed orientation of the SO(2) group.