Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. I 2-Nitrophenoxides of Group 1

1998 ◽  
Vol 51 (8) ◽  
pp. 707 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Todd M. Shand ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Room Temperature ◽  
Closed Shell ◽  
Aromatic Rings ◽  
X Ray ◽  
Metal Atoms ◽  
Metal Derivatives ◽  
Derivatives Of ◽  
Fourth Coordination ◽  
Group 1 ◽  
Oxygen Atoms

Room-temperature, single-crystal X-ray studies are recorded for the variously hydrated Group 1 metal derivatives of 2-nitrophenol (2-npH = C6H5NO3). A provisional determination is reported for Li(2-np).½H2O, set as monoclinic, P21/c, a 3·535(3), b 15·06(1), c 24·42(2) Å, β 91·7(1)°, Z = 8, conventional R on F currently 0·18 for No 875 ‘observed’ (I > 3σ(I)) reflections. Na(2-np).H2O is monoclinic, C2/c, a 34 ·23(2), b 3·624(4), c 35·48(2) Å, β 91·24(4)°, Z = 24, R 0·060 for No 1371. Rb(2-np).½ H2O is monoclinic, C2/c (isomorphous with the previously determined potassium analogue), a 25·269(9), b 5·381(5), c 12·010(3) Å, β 105·35(3)°, Z = 8, R 0·046 for No 1380. Cs(2-np).½H2O is monoclinic, P21/n, a 7·648(3), b 26·19(1), c 8·713(6) Å, β 111·75(2)°, Z = 8, R 0·061 for No 2347. All compounds except the lithium derivative are two-dimensional polymeric sheets in which the aromatic rings project to either side of a core of metal atoms coordinated by a web of 2-nitrophenoxide oxygen atoms in various bridging functionalities. The lithium compound is a novel ‘stair’ polymer with two crystallographically independent lithium atoms at successive independent Li–O crossbars, the oxygen atoms of which are phenoxide-Oof each of the two independent ligands. The lithium atoms are alternately four- and five-coordinate, the fourth coordination site of the first being occupied by the water molecule oxygen atom, while the fourth and fifth sites of the second are occupied by the cis-2-nitro oxygen atoms of the two ligands

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. IV [Acid Salts] of the 4-Nitrophenoxides of Group 1

1998 ◽  
Vol 51 (8) ◽  
pp. 747 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Hydrogen Atom ◽  
Metal Ions ◽  
Room Temperature ◽  
Closed Shell ◽  
X Ray ◽  
Salt Structure ◽  
Group 1 ◽  
Parent Ligand ◽  
Oxygen Atoms ◽  
Acid Salts

Room-temperature single-crystal X-ray studies are recorded for a number of ‘acid salts’ formed between Group 1 salts of 4-nitrophenol, M(4-np), and the parent ligand 4-npH, variously hydrated. The 1 : 1 salts M(4-np)(4-npH).x H2O are found for all of M = Li, Na, K, Rb and Cs. The lithium adduct (tetrahydrate) is monoclinic, C2/c, a 19·438(4), b 11·207(2), c 7·421(2) Å, β 91·38(2)°, Z = 4, conventional R on |F| being 0·043 for 1369 independent ‘observed’ (I > 3σ(I)) diffractometer reflections. The sodium adduct (dihydrate) is monoclinic, C2, a 2·174(3), b 3·674(2), c 10·358(1) Å, β 117·21(1)°, Z = 2, R 0·035 for No 1092; the potassium adduct (monohydrate) is monoclinic, C 2/c, a 22·10(1), b 3·798(3), c 21·270(6) Å, β 120·97(4)°, Z = 4, R 0·050 for No 1065. The isomorphous rubidium and caesium monohydrates are triclinic, P-1, a ≈ 11·9, b ≈ 10·2,c ≈ 6·3 Å, α ≈ 90, β ≈ 92, γ ≈ 112°, Z = 2, R 0·042, 0·028 for No 2340, 3053 respectively. For M = Rb, a 1 : 3 adduct Rb(4-np).3(4-npH) is also obtained (with an isomorphous thallium counterpart recorded elsewhere): a 12·143(5), b 11·50(1), c 11·36(1) Å, α 114·38(9), β 110·54(6), γ 96·73(6)°, Z = 2, R 0·034 for No 3945. The lithium salt may be represented as [Li(OH2)4]+ (4-npH.4-np)½-. The cation lies disposed about a crystallographic 2 axis; the anion, close to an axis, confronts its rotational image, with the associated hydrogen atom modelled as disordered between them, rather than located on the 2 axis. The sodium salt is a sheet structure, the six-coordinate sodium atoms being disposed on a crystallographic 2 axis and linked up that axis ... Na(µ-O)2Na(µ-O)2Na ... by bridging water molecule oxygen atoms, while symmetry-related trans O-nitrophenoxide moieties are bridged by confronting phenoxide oxygen atoms about an associated hydrogen atom provisionally disposed on a 2 axis also. The potassium salt structure is developed from this array, modelled with disordered potassium atoms, now lying off the 2 axis, 0·922(2) Å apart. In the rubidium/caesium structure, columns of oxygen-bridged metal ions are disposed about c, crosslinked by O-nitro-bonded phenoxide moieties, with confronting phenoxide oxygen atoms about a shared associated hydrogen.

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. II 4-Nitrophenoxides of Group 1

1998 ◽  
Vol 51 (8) ◽  
pp. 723 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Molecular Complex ◽  
Room Temperature ◽  
Three Dimensional ◽  
Closed Shell ◽  
The Other ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Metal Atoms ◽  
Group 1

Room-temperature single-crystal X-ray studies are recorded for 4-nitrophenoxide (4-np¯) salts, variously hydrated, of the Group 1 metals, M(4-np-).χH2O, for M = Li, Na (redetermination), K (already recorded), Rb and Cs. Li(4-np).3H2O is monoclinic, space group Pc, a 11·359(3), b 7·518(3), c 10·855(4) Å, β 90·56(3)°, Z = 4; conventional R on |F| was 0·056 for No 2098 independent `observed" (I > 3σ(I)) reflections. Na(4-np).2H2O is orthorhombic, Ima2, a 6·888(6), b 19·699(8), c 6·436(8) Å, Z = 4, R 0·031 for No 664. Rb(4-np).H2O is orthorhombic, Pbca, a 11·82(3), b 19·724(7), c 7·199(1) Å, Z = 8, R 0·036 for No 1465. Cs(4-np).3H2O is monoclinic, P 21/c, a 13·337(2), b 12·770(5), c 6·311(2) Å, β 100·56(3)°, Z = 4, R 0·031 for No 2636. Whereas the lithium compound is essentially a discrete mononuclear neutral molecular complex [(4-np-O)Li(OH2)3] with four-coordinate lithium, the other compounds exhibit two- or three-dimensional sheet polymer structures with 4-nitrophenoxide moieties providing O-C6H4-NO2 head-tail connecting motifs between successive metal atoms.

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. III 2/4-Nitrophenoxides of Univalent Heavy Metals

1998 ◽  
Vol 51 (8) ◽  
pp. 735 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Closed Shell ◽  
Two Dimensional ◽  
Nitrogen Base ◽  
Coinage Metal ◽  
Aromatic Carbon ◽  
X Ray ◽  
Dimensional Network ◽  
Oxygen Atoms

Room-temperature single-crystal X-ray studies are recorded for 2- and 4-nitrophenoxide salts of silver(I) and thallium(I), M(2-np) and Tl(4-np) (anhydrous), and Ag(4-np).H2O. Ag(2-np) is monoclinic, P21/c, a 9·012(4), b 5·743(5), c 12·594(5) Å, β 104·34(4)°, Z = 4; conventional R on |F| was 0·042 for No 1378 independent ‘observed’ (I > 3σ(I)) reflections. Tl(2-np) is monoclinic, C2/c, a 27·250(3), b 3·712(1), c 15·147(3) Å, β 114·41(1)°, Z = 8, R 0·025 for No 1346. Ag(4-np).H2O is monoclinic, P21/a, a 5·613(6), b 13·191(7), c 9·844(5) Å, β 92·50(6)°, Z = 4, R 0 ·033 for No 622. Tl(4-np) is tetragonal, I 41/a, a 18·037(8), c 8·979(8) Å, Z = 16, R 0·043 for No 924. An acid salt of the latter, Tl(4-np).(4-npH)3, triclinic, P-1, a 11·861(8), b 11·45(1), c 11· 423(1) Å, α 114·00(6), β 109·78(5), γ 96·87(7)°, Z = 2, R 0·042 for No 3814, is isomorphous with its rubidium analogue. These comprise a novel array of structures: although the structures of the silver(I) complexes are two-dimensional sheets with familiar head-tail connecting ligands, a strong silver-aromatic carbon interaction is found in Ag(2-np) (Ag–C 2·496(5) Å). Tl(2-np) and Tl(4-np) both present unusual forms related to the stair-polymer and cubane adducts found in 1 : 1 coinage metal(I)/halide-unidentate nitrogen base adducts; Tl(2-np) is a double-stranded stair-polymer array, with the phenoxide oxygen atoms incorporated in the stair and the nitro oxygen atoms linking successive thallium atoms. The structure of Tl(4-np) is based on a tetranuclear cubane motif of -4 symmetry, [Tl(O-phenoxide)]4, these being linked into a three-dimensional network by further Tl · · · O-nitro interactions from adjacent units. The structure of silver(I) picrate monohydrate, isomorphous with its sodium counterpart, is also recorded: monoclinic, C 2/m, a 12·818(7), b 20·208(8), c 3· 741(1) Å, β 88·25(3)°, Z = 4, R 0·047 for No 1042, void of any significant Ag · · · C contacts.

Synthesis and X-ray powder diffraction data of transition metal derivatives of maleic acid. I. M2+(C4H3O4−)2⋅4H2O (M2+=Mn, Fe, Co, Ni, and Zn)

2002 ◽  
Vol 17 (2) ◽  
pp. 139-143 ◽  
Author(s):  
A. Briceño ◽  
T. González ◽  
G. Díaz de Delgado ◽  
R. Guevara ◽  
J. M. Delgado
Keyword(s):  
Transition Metal ◽  
Powder Diffraction ◽  
Maleic Acid ◽  
Room Temperature ◽  
Slow Evaporation ◽  
X Ray ◽  
Metal Derivatives ◽  
Diffraction Patterns ◽  
Triclinic Unit Cell ◽  
Derivatives Of

Five transition metal derivatives of maleic acid with general formula, M2+(C4H3O4−)2⋅4H2O (M2+=Mn, Fe, Co, Ni, and Zn) were prepared by slow evaporation of the aqueous solution at room temperature. Their X-ray powder diffraction patterns were recorded and evaluated. These materials are isostructural and crystallize in a triclinic unit cell. The volume of the cells vary linearly between that of the Ni complex [V=314.65(7) Å3: a=5.1769(8) Å, b=7.317(1) Å, c=9.140(2) Å, α=108.42(2)°, β=104.61(1)°, γ=92.87(1)°] and the volume of the Mn-derivative [V=330.30(8) Å3: a=5.322(1) Å, b=7.375(1) Å, c=9.752(2) Å, α=115.48(2)°, β=106.64(2)°, γ=86.63(2)°].

The direct electrochemical synthesis of some metal derivatives of lapachol

1997 ◽  
Vol 75 (5) ◽  
pp. 499-506 ◽  
Author(s):  
E.H. De Oliveira ◽  
G.E.A. Medeiros ◽  
C. Peppe ◽  
Martyn A. Brown ◽  
Dennis G. Tuck
Keyword(s):  
Electrochemical Oxidation ◽  
Copper Atom ◽  
Electrochemical Synthesis ◽  
Acetonitrile Solution ◽  
Triclinic Space Group ◽  
X Ray ◽  
Metal Anode ◽  
X Ray Crystallography ◽  
Metal Derivatives ◽  
Derivatives Of

The electrochemical oxidation of a sacrificial metal anode (M = Zn, Cd, Cu) in an acetonitrile solution of 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone, lapachol, C15H14O3 (=HL) gives ML2. The results are in keeping with earlier work on direct electrochemical synthesis in related systems. Adducts with 2,2′-bipyridine (bpy) and N,N,N′,N′-tetramethylethanediamine (tmen) have also been prepared. The structure of the 2,2′-bipyridine adduct of Cu(lapacholate)2 has been established by X-ray crystallography. The parameters are triclinic, space group [Formula: see text], a = 12.748(59) Å, b = 13.859(49) Å, c = 11.770(59) Å, α = 108.30(4)°, β = 108.08(3)°, γ = 68.94(3)°, Z = 2, R = 0.059 for 2256 unique reflections. The copper atom is in a distorted CuN2O2O2′ environment. The mechanism of the formation of this Cu(lapacholate)2 is discussed. Keywords: electrochemical synthesis, lapachol, X-ray crystallography, copper(II) complex.

scholarly journals Nucleofugal behavior of a β-shielded α-cyanovinyl carbanion

2018 ◽  
Vol 14 ◽  
pp. 3018-3024
Author(s):  
Rudolf Knorr ◽  
Barbara Schmidt
Keyword(s):  
Michael Addition ◽  
Carbonyl Compounds ◽  
Room Temperature ◽  
Experimental Conditions ◽  
Metal Free ◽  
Metal Derivatives ◽  
Carbonyl Addition ◽  
Derivatives Of

Sterically well-shielded against unsolicited Michael addition and polymerization reactions, α-metalated α-(1,1,3,3-tetramethylindan-2-ylidene)acetonitriles added reversibly to three small aldehydes and two bulky ketones at room temperature. Experimental conditions were determined for transfer of the nucleofugal title carbanion unit between different carbonyl compounds. These readily occurring retro-additions via C–C(O) bond fission may also be used to generate different metal derivatives of the nucleofugal anions as equilibrium components. Fluoride-catalyzed, metal-free desilylation admitted carbonyl addition but blocked the retro-addition.

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. VII Acid Salts of the 4-Nitrophenoxides of Group 2

1998 ◽  
Vol 51 (8) ◽  
pp. 785 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Room Temperature ◽  
Calcium Salt ◽  
Three Dimensional ◽  
Closed Shell ◽  
The Other ◽  
X Ray ◽  
C 23 ◽  
Structure Determinations ◽  
Group 2 ◽  
Acid Salts

Room-temperature single-crystal X-ray structure determinations are recorded for a number of Group 2 4-nitrophenoxide acid salts, variously hydrated M(4-np)2.x(4-npH).yH2O. Ca(4-np)2.2(4-npH).8H2O is monoclinic, P 21/n, a 30·52(1), b 10·027(1), c 23·65(2) Å, β 116·3(5)°, Z = 8, conventional R on |F| being 0·058 for No 5092 independent ‘observed’ (I > 3s(I)) reflections. Sr(4-np)2.2(4-npH).8H2O, based on a subcell of the former, is monoclinic, P 21/c, a 15·576(5), b10·081(6), c 24·20(2) Å, β 117·99(5)° , Z = 4, R 0·054 for No 2908. Ba(4-np)2.2(4-npH).4H2O is orthorhombic, Fdd2, a 28·01(1), b 19·90(1), c 10·692(7)Å, Z = 8, R 0·028 for No 1967. The strontium array (and that of the calcium salt developed from it) may be represented as [(H2O)6Sr(4-npH.4-np)] (4-npH.4-np), a neutral ligand being unsymmetrically chelated to the strontium through the nitro group, with a quasi-parallel counter ion hydrogen-bonded to it by phenoxide confrontation. The other two 4-np residues make up a similar phenoxide-confronting pair (4-npH.4-np), the hydrogen being more intimately associated with one moiety. The barium salt is also an interesting array: the 10-coordinate barium lies on a crystallographic 2 axis, in an environment of two pairs of symmetry-related nitro-chelating ligand anions, and a pair of nitro-O coordinating neutral 4-npH ligands; the whole [(H2O)4Ba(4-np)2(4-npH)2] array may be envisaged as a single neutral (super)molecule. Hydrogen bonds between confronting phenoxides of the neutral 4-npH components of the parent and the 4-np- components of neighbouring molecules link the whole into a three-dimensional array.

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. V 2-Nitrophenoxides of Group 2

1998 ◽  
Vol 51 (8) ◽  
pp. 761 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Water Molecule ◽  
Metal Ions ◽  
Single Crystal ◽  
Room Temperature ◽  
Closed Shell ◽  
Magnesium Salt ◽  
Water Molecules ◽  
One Dimensional ◽  
X Ray ◽  
Group 2

Room-temperature single-crystal X-ray studies are recorded for 2-nitrophenoxide salts of Group 2 metals, variously hydrated M(2-np)2.xH2O, M = Mg, Ca, Sr; the structure of the barium analogue has been previously recorded. Mg(2-np)2.2H2O is monoclinic, P21/a, a 7·377(1), b 7·518(1), c 12·877(3) Å, β 106·58(2)°, Z = 2; conventional R on |F| 0·13 for No 508 independent ‘observed’ (I > 3σ(I)) reflections. Ca(2-np)2.H2O is monoclinic, C2, a 25·92(1), b 7·176(3), c 3·660(4) Å, β 93·66(5)°, Z = 2, R 0·061 for No 541. M(2-np)2.4H2O, M = Ca, Sr, are isomorphous, monoclinic, C2/c, a ≈ 31·3, b ≈ 8·1, c ≈ 12·8 Å, β 103°, Z = 8; R was 0·056, 0·055 forNo 1988, 1744 respectively. The magnesium salt is a discrete molecular array disposed about a crystallographic inversion centre with chelating phenoxide ligands: trans-[Mg(2-np)2(OH2)2]. The calcium monohydrate salt is a novel one-dimensional polymer with a ... Ca(µ-O)2Ca(µ-O)2Ca ... spine, the ligand pairs chelating the calcium with phenoxide-O additionally bridging. The seven-coordinate calcium atoms lie on the crystallographic 2 axis with the water molecule, also on that axis, making up a seven-coordinate environment. The tetrahydrate is also a one-dimensional polymer with a similar spine, the bridging oxygen atoms derivative of water molecules. A chelating ligand and two further water molecules make up an eight-coordinate metal environment, with the free anions interleaving stacks of coordinated anions up c.

Pentakis(methoxycarbonyl)cyclopentadiene Chemistry. XIII. Some Metal Derivatives of 1-Methyl-2,3,4,5-tetrakis(methoxycarbonyl)cyclopentadiene. X-Ray Structure of Au[C5Me(Co2Me)4](PPh3)

1989 ◽  
Vol 42 (11) ◽  
pp. 1847 ◽  
Author(s):  
MI Bruce ◽  
PA Humphrey ◽  
ML Williams ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Monoclinic Space Group ◽  
Methyl Group ◽  
Space Group ◽  
X Ray ◽  
Ring Carbon ◽  
Metal Derivatives ◽  
Derivatives Of

Reactions of HC5Me(CO2Me)4 or TI[C5Me(CO2Me)4] with appropriate precursors have afforded the compounds ML2{C5Me(CO2Me)4}2 (M = Mn , L = H2O; M = Cu, L = MeOH ), Rh (ŋ4C8H12 )}ŋ5 -C5Me(CO2Me)4}, Rh {C5Me(CO2Me)4]2,RU(ŋ-C5H5){η5(C5Me(CO2Me)4}, Cu{C5Me(CO2Me)4}-(PPh3)2 and M{C5Me(COP2Me)4}(PPh3)(M=Ag or Au). There appear to be no significant differences between these compounds and analogous species derived from HC5(CO2Me)5, except for the expected spectroscopic changes. The molecular structure of Au{C2Me(CO2Me)4}(PPh3) closely resembles that of Au{C5(CO2- Me)5}(PPh3); the methyl group is on the ring carbon adjacent to that which most closely interacts with the Au(PPh3) group. Crystals are monoclinic, space group P21/c, with a 10.313(2), b 10-388(3), c 28.637(11)�, β 97.01(3)�, Z 4; 3571 data with I> 3σ) were refined to R 0.037, R′0.033.

Neutron diffraction studies of the actinide oxides II. Thermal motions of the atoms in uranium dioxide and thorium dioxide between room temperature and 1100 °C

1963 ◽  
Vol 274 (1356) ◽  
pp. 134-144 ◽  
Keyword(s):  
Room Temperature ◽  
Characteristic Temperature ◽  
Relaxation Effect ◽  
Thorium Dioxide ◽  
Metal Atoms ◽  
Fluorite Type ◽  
Thermal Displacements ◽  
Actinide Oxides ◽  
The Mean ◽  
Oxygen Atoms

The mean-square thermal displacements of the atoms in U 0 2 and T h 0 2 have been determined as a function of temperature from the analysis of two-dimensional diffraction data. In the range investigated, 20 to 1100°C, the oxygen atoms vibrate more strongly than the metal atoms and at each temperature the displacements of the metal and oxygen atoms are slightly less in T h 0 2 than in U 0 2. The interpretation of these results gives a Debye characteristic temperature which is independent of tem temperature above 400 °C and equal to 377 °K for U 0 2 and 393 °K for T h 0 2. As the temperature rises, the oxygen atoms tend to be displaced from the fluorite-type sites at 1/4 1/4 1/4. . . towards the large interstitial holes at 1/2 1/2 1/2.... At 1000°C the mean atomic co-ordinates of the oxygen atoms are 1/4+ 8 1/4+8 1/4 ...where, 8 — 0*016 for UO 2 and 8 = 0.014 for ThO 2 . This relaxation effect indicates either that the oxygens are disordered or that they vibrate anharmonically across the 1/4 1/4 1/4. . . positions.

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