Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. I. Some Adducts of Group 2 Halides With Acetonitrile

1996 ◽  
Vol 49 (1) ◽  
pp. 27 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Coordination Sphere ◽  
Molecular Species ◽  
Room Temperature ◽  
Linear Array ◽  
Nitrogen Base ◽  
X Ray ◽  
Unusual Combination ◽  
Anionic Species ◽  
Group 2 ◽  
O 352

Recrystallization of anhydrous Group 2 halides from anhydrous acetonitrile has yielded, in a number of cases, adducts MX2.nMeCN suitable for characterization by room-temperature single-crystal X-ray studies, which revealed novel stereochemical types. Magnesium(II) bromide yields a trisolvate, ionic with disproportionated ligand arrays, as [Mg(NCMe)6][MgBr4] (1), an unusual combination of homoleptic cationic and anionic species. Crystals are triclinic, Pī , a 19.129(1), b l6.870(8), c 8.737(7) Ǻ,α 83.96(3), β 87.93(4), γ 65.24(2)�, Z=4 f.u .; R was 0.068 for N o 3181 'observed' (I > 3σ(I)) reflections. Mg-N are 2.12(2)-2.18(2) Ǻ, and Mg-Br are 2.452(7)-2.481(6) Ǻ. Calcium(II) bromide, by contrast, yields a disolvate , an infinite polymer, with the two MeCN ligands trans in a quasi-octahedral coordination sphere, and the polymer comprising a ... Ca(μ-Br)2Ca(μ-Br)2... linear array. Crystals of 1:2 CaBr2/MeCN (2) are orthorhombic, Pbam , a l4.252(3), b 8.539(2), c 4.2088(6) Ǻ, Z=2 f.u .; R 0.043 for N o 352. Ca-N is 2.46(1) Ǻ, and Ca-Br 2.8765(9) Ǻ. CaI2 and SrI2 yield pentasolvates as neutral, molecular species [( MeCN )5MX2] (3) and (4), with the halides trans in a pentagonal bipyramidal coordination sphere. They are isomorphous . orthorhombic, Pcab , a ≈ 18.4, b ≈ 14.6, c ≈ 14.3 Ǻ, Z = 8 f.u .; R were 0.042 and 0.059 for N o 2297 and 1489 respectively. Ca-I are 3.132(2), 3.116(2) Ǻ and Sr -I are 3.265(3), 3.238(3) Ǻ, while Ca-N are (range) 2.518(8)-2.566(8) Ǻ and Sr -N 2.68(2)-2.73(2) Ǻ.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. VII. Some Complexes of Group 2 Metal Halides With Aromatic N,N'-Bidentate Ligands

1996 ◽  
Vol 49 (1) ◽  
pp. 99 ◽  
Author(s):  
BW Skelton ◽  
AF Waters ◽  
AH White
Keyword(s):  
Room Temperature ◽  
The Novel ◽  
Bidentate Ligands ◽  
Nitrogen Base ◽  
One Dimensional ◽  
X Ray ◽  
L System ◽  
L Systems ◽  
Group 2 ◽  
Structural Characterizations

Syntheses and room-temperature single-crystal X-ray structural characterizations are recorded for a number of adducts of Group 2 halides with the aromatic N,N′- bidentate ligands L = 2,2'-bipyridine ( bpy ) and 1,10-phenanthroline ( phen ). One adduct of 1 : 1 MX2/L stoichiometry is recorded: [( bpy )Ca(μ-Br)(4/2)](∞ ׀ ∞) (1) is monoclinic, C 2/c, a l7.102(5), b 9.845(1), c 7.600(2) Ǻ, β 107.65(2)°, Z = 4 f.u .; conventional R on #1472; F ׀ at convergence was 0.057 for No 817 independent 'observed' ( I > 3σ(I)) reflections, the compound being a one-dimensional polymer… CaL (μ-Br)2CaL(μ-Br)2…, with six-coordinate calcium, cis-CaN2(μ-Br)4, on a twofold axis. 1 : 2 MX2/L systems have been described for two types of array: [( bpy )2CaI2] (2), orthorhombic, Pnca, a 16.914(4), b 13.80(1), c 9.290(4) Ǻ, Z = 4 f.u .; R 0.039 for No 1738, is discrete mononuclear, containing cis-CaN4I2 six-coordinate calcium, whereas the barium analogue is an infinite one-dimensional polymer, [( bpy )2Ba(μ-I)(4/2)](∞׀ ∞) (3), triclinic, Pī, a 11.318(2), b 11.078(2), c 9.206(4) Ǻ, α 80.87(2), β 77.52(2), γ 87.53(1)°, Z = 2 f.u .; R 0.032 for No 4154, with eight-coordinate (N2)2Ba(μ-I)4. The perchlorate analogue, [( bpy )2Ba(μ-OClO2O)(4/2)](∞ ׀ ∞) (4), although of similar stoichiometry, has a trans-rather than a cis-linked chain; it is monoclinic, P 21/c, a 6.606(2), b 18.661(7), c 19.440(8) Ǻ, β 109.45(4)°, Z = 4 f.u .; R 0.044 for No 4060, with μ-I replaced by O,O'-ClO4 bridging units and eight-coordinate barium, (N2)2BaO4. The 1 : 3 MX2/L system is represented (as its hemi( bipyridine ) 'solvate') by mononuclear [( bpy )3SrI2].0.5bpy (5), monoclinic, P 21/c, a 20.834(8), b 9.735(4), c 18.460(7) Ǻ, β 114.87(3)°, Z = 4 f.u .; R 0.039 for No 3711, containing eight-coordinate strontium, [(N2)3SrI2]; there is also an isomorphous calcium/ perchlorate analogue [( bpy )3Ca(OClO3)2].0.5bpy (6), a 21.413(6), b 9.813(4), c 18.659(2) Ǻ, β 115.67(2)°, R 0.057 for No 3090, in which unidentate O-ClO4 ligands replace the iodine about the metal atom. A 1 : 4 adduct is obtained with CaI2/phen; ionic [Ca( phen )4] I2 (7), triclinic, Pī , a 14.703(3), b 13.292(3), c 11.38(1) Ǻ, α 92.78(4), β 96.15(4), γ 105.22(2)°, Z = 2 f.u ., R 0.053 for No 3658, contains eight-coordinate Ca(N2)4 arrays, while the novel 1 : 5 adduct [ Ba ( phen )4] I2.MeCN (8) is triclinic, Pī , a 12.170(6), b 13.760(7), c 18 254(8) Ǻ, α 77.05(9), ,β 71.96(4), γ 70.83(9)°, Z = 2 f.u ., R 0.040 for No 4447, containing 10-coordinate barium, [ Ba (N2)5]. A 1 : 4 adduct formed with BaBr2 is [ BrBa( phen )4] Br.MeOH (9), triclinic, Pī , a 17.748(4), b 17.418(2), c 15.535(7) Ǻ, α 91.63(2), β 100.53(3), γ 115.39(1)°, Z = 4 f.u ., R 0.062 for No 4092, containing nine-coordinate barium, [ BrBa (N2)4].

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. VI. Mixed Oligodentate-Aliphatic-Base/Oxygen Ligand Adducts

1996 ◽  
Vol 49 (1) ◽  
pp. 87 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Mixed Ligand ◽  
Metal Salts ◽  
Precise Description ◽  
Nitrogen Base ◽  
X Ray ◽  
Oxygen Ligand ◽  
Group 2 ◽  
Ligand Species

In the course of synthesizing oligodentate aliphatic nitrogen base adducts of Group 2 metal salts, a number of mixed- ligand species have been isolated with oxygen ligands , and characterized by room-temperature single-crystal X-ray studies. BaCl2.4en.H2O ≡[(en)4Ba(OH2)] Cl2 (1) is monoclinic, P 21/c, a 9.456(4), b 14.953(6), c 14.82(1) Ǻ, β 100.78(6)°, Z = 4 f.u ., R 0.043 for No 1862 independent 'observed' (I > 3σ(I)) diffractometer reflections. Ba -N range between 2.900(9) and 2.97(1) Ǻ, and Ba-O is 2.779(8) Ǻ in the nine-coordinate BaN8O environment. CaCl2.2dien.H2O ≡ [( dien )2Ca(OH2) Cl ] Cl (2) is monoclinic, P 21/c, a 10.808(4), b 11.999(4), c 15.71(1) Ǻ, β 123.58(4)°, Z = 4 f.u ., R 0.050 for No 3134; CaBr2.2dien.2H2O ≡ [( dien )2Ca(OH2)2] Br2 (3) is monoclinic, P 21/c, a 18.001(3), b 11.983(6), c 21.562(5) Ǻ, β 124.97(2)°, Z = 8 f.u ., R 0.045 for No 2858; CaBr2.2dien.2MeOH ≡ [( dien )2Ca( HOMe )2] Br2 (4) is orthorhombic, P212121, a 16.620(8), b 12.78(1), c 9.765(4) Ǻ, Z = 4 f.u ., R 0.073 for No 878. In (2)-(4), the cation configurations are similar, being of the form [L2Ca( dien )2], L (L') being the unidentate ligand, with the eight-coordinate calcium environments [L2Ca(N3)2] in a common isomeric configuration, the two ligands L being cis in an array of quasi-2 symmetry. Ca- Cl in (2) is 2.834(1) Ǻ; Ca-N generally range between 2.52(5) and 2.64(1) Ǻ; Ca-O(H2O) is 2.418(2) in (2), 2.434(7)-2.496(7) Ǻ in (3), while Ca-O( MeOH ) in (4) are 2.43(2) and 2.43(2) Ǻ. [Mg(HOMe)6] I2.2tmeda (5) ( tmeda = Me2N(CH2)2NMe2), orthorhombic, Pbca, a 23.423(8), b 15.306(4), c 9.345(1) Ǻ, Z = 4 f.u ., R 0.052 for No 1928, provides a usefully precise description for the centrosymmetric cation, Mg-O being 2.069(4), 2.080(4), 2.096(5) Ǻ, with Mg-O-C 128.4(4) l28.9(4), l29.7(4)°. [( tmeda )SrI2 ( HOMe )3].½tmeda (6), monoclinic, P 21/c, a 7.730(1), b 35.493(9), c 11.081(2) Ǻ, β 126.49(1)°, R 0.042 for No 3161, has a seven-coordinate, quasi-pentagonal bipyramidal SrN2I2O3 array about the metal with trans-iodines.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. IX. Some Complexes of Group 2 Metal Halides With 2,2':6',2"-Terpyridine

1996 ◽  
Vol 49 (1) ◽  
pp. 137 ◽  
Author(s):  
BW Skelton ◽  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Nitrogen Base ◽  
Space Group ◽  
Trigonal Symmetry ◽  
X Ray ◽  
Space Groups ◽  
Structure Determinations ◽  
Group 2 ◽  
A Site

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for a number of adducts of MX2.ntpy stoichiometry of salts of Group 2 metals, MX2, with 2,2':6',2"-terpyridine ( tpy ). ' Homoleptic' adducts, [M( tpy )3] X2, are found in space groups with trigonal symmetry, with M located on a site of at least 3 symmetry, the structures being derivative of the P 62c array found in [ Pb ( tpy )3] (ClO4)2, but with variations in anion and cation stackings . [M( tpy )3] I2.~1.7MeOH, M = Ca (1), Sr (2), are trigonal , P3c1, a ≈ 13, c ≈ 15.3 Ǻ, Z = 2 f.u., conventional R on ׀ F ׀ being 0.050, 0.086 for No 894, 865 independent 'observed' (I > 3σ(I)) reflections respectively. [ Sr ( tpy )3] Br2.2MeOH (3), although similar, is modelled in space group P3c1, a 13.040(4), c 15.13(1) Ǻ, Z = 2 f.u ., R 0.041 for No 447. [( tpy )2BaI2] (4) is monoclinic, P 21/c, a 10.812(4), b 16.740(5), c 17.458(4) Ǻ, β 109.39(2)°, Z = 4 f.u ., R 0.042 for No 3256. [( tpy )2Ba(O2ClO2)2] (5) is triclinic, Pī , a 14.220(4), b 11.212(2), c 10.511(2) Ǻ, α 65.66(2), β 87.32(2), γ 88.92(2)°, Z = 2 f.u ., R 0.029 for No 4676.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. III. Some Mixed-Ligand Complexes With Pyridine Base and Oxygen Donors

1996 ◽  
Vol 49 (1) ◽  
pp. 47 ◽  
Author(s):  
DL Kepert ◽  
BW Skelton ◽  
AF Waters ◽  
AH White
Keyword(s):  
Room Temperature ◽  
Preceding Paper ◽  
Mixed Ligand ◽  
Water Molecules ◽  
Two Dimensional ◽  
Nitrogen Base ◽  
X Ray ◽  
Pyridine Base ◽  
Group 2 ◽  
Oxygen Donors

In association with the report of a number of homoleptic pyridine base adducts of Group 2 salts in the preceding paper, a number of mixed-ligand compounds have been synthesized and characterized by room-temperature single-crystal X-ray studies. MgI2.2H2O.6py ≡ [trans-( py )4Mg(OH2)2]I2.2py (1) is monoclinic, P21/c, a 10.47(1), b 10.0400(8), c 32.77(1) Ǻ, β 92.34(6)°, Z = 4; R was 0.053 for No = 2990 independent, observed (I > 3σ(I)) diffractometer reflections. Mg-O are 2.063(8) and 2.061(8), Mg-N ranging between 2.19(1) and 2.23(1) Ǻ. MgI2.4H2O.8(3,5-dmpy)≡[trans-(3,5-dmpy)2Mg(OH2)4]I2.6(3,5-dmpy) (2) is orthorhombic, Pcab , a 22.203(6), b 17.023(8), c 16.548(7) Ǻ, Z = 4 f.u .; R 0.045 for N o 2457. Mg-O are 2.026(5) and 2.082(5), and Mg-N 2.267(6) Ǻ in the centrosymmetric cation, with which the aggregate of anions and solvent form a discrete hydrogen-bonded cluster. CaBr2.2H2O.4(2-mpy) ≡ [trans-CaBr2(OH2).2(2-mpy)2].2(2-mpy) (3) is monoclinic, P 21/c, a 7.076(1), b 9.329(3), c 21.957(2) Ǻ, β 98.34(1)°, Z = 2 f.u .; R 0.076 for No 1599; Ca-Br, N, O are 2.840(1), 2.56(1), 2.355(6) Ǻ respectively; its 3-mpy counterpart (4) has a very similar cell but with b and c transposed; R was 0.047 for No 2116, and Ca-Br, N, O 2.8902(6), 2.500(5), 2.344(3) Ǻ. Sr (ClO4)2.3py.dmf ≡ [ Sr (O2ClO2)2( py )3(O- dmf )] (5) is monoclinic, P21, a 8.814(2), b 16.985(7), c 9.499(1) Ǻ, β 114.97(1)°, Z = 2; R 0.047 for No 1717. The strontium is eight-coordinate: Sr -O(ClO4) are 2.644(8)-2.69(1), Sr-N 2.64(1)-2.69(1), Sr -O( dmf ) 2.417(9) Ǻ. The other two compounds, Ba (ClO4)2.H2O.L (L = py (6), 3-mpy (7)), are two-dimensional polymers, linked by bridging perchlorate ions and water molecules. Compound (6) is orthorhombic, Pnna , a 24.098(3), b 10.444(1), c 4.871(3) Ǻ, Z = 4 f.u ., R 0.025 for N o 688: the barium is 11-coordinate Ba (O(H2O))2(O(ClO4))8N with m symmetry, Ba -N 2.889(7), Ba-O(H2O)2.943(4), Ba-O(ClO4) 2.844(6)-2.942(5) Ǻ. Compound (7) is monoclinic, P 21/c, a 7.421(4), b 24.479(8), c 7.293(7) Ǻ, β 104.80(6)°, Z = 4 f.u ., R 0.041 for N o 2033; the barium is nine-coordinate Ba (O(H2O))2(O(ClO4))6N, Ba-N 2.839(7), Ba -O(H2O) 2.791(5), 3.049(5), Ba-O(ClO4) 2.753(6)-2.936(6) Ǻ.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. II. Some Adducts of Group 2 Salts With Pyridine

1996 ◽  
Vol 49 (1) ◽  
pp. 35 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Metal Atom ◽  
Room Temperature ◽  
Site Symmetry ◽  
Nitrogen Base ◽  
Coordination Environment ◽  
X Ray ◽  
Pyridine Nitrogen ◽  
The Subject ◽  
Group 2 ◽  
A Site

Recrystallization of Group 2 halides from pyridine ( py ) solution has yielded, in a number of cases, crystalline adducts MX2.npy which have been the subject of room-temperature single-crystal X-ray structural characterization. MgBr2.6py (1) is orthorhombic, Ccca, a 11.575(2), b 14.999(4), c 17.292(2) Ǻ, Z = 4; conventional R on [F] for No = 752 'observed' (I > 3σ(I)) reflections was 0.043. The compound is formulated as [( py )4MgBr2].2py, the metal atom on a site of 222 symmetry having a trans-X2MN4 coordination environment. With CaCl2, a 1:2 adduct (2) is formed, orthorhombic, Fdd2, a 33.83(1), b 18.143(2), c 3.981(7) Ǻ, Z = 8 f.u ., R 0.040 for No 451; the complex is an infinite polymer along c, [( py )2CaCl2](∞ ׀ ∞), the…CaCl2CaCl2Ca…spine having six-coordinate, octahedral calcium environments in which the pyridine nitrogen atoms are bound trans to either side, with the calcium site symmetry being 2. With SrBr2, a 1:5 adduct (3) is found, mononuclear, [( py )5SrBr2], with the metal atom in a pentagonal bipyramidal coordination environment (orthorhombic, Pcab , a 18.611(5), b 17.768(7), c 17.411(7) Ǻ, Z = 8; R 0.060 for No 949). With BaI2, a 1:6 adduct (4) is obtained, [( py )6BaI2], the eight-coordinate barium atom lying on a crystallographic 2 axis in a monoclinic C2/c cell, Z = 4, a 18.311(2), b 9.960(3), c l8.856(8) Ǻ, β 99.28(3)° (R 0.031 for No 2279), with the iodide atoms occupying a pair of B sites in one of the trapezoidal planes of a quasi-dodecahedral array. [(2-mpy)2MgBr2] (5), 2-mpy=2-methylpyridine, is of interest, offering a four-coordinate N2MgBr2 array (triclinic, Pī, a 8.046(3), b 8.873(3), c 11.475(1) Ǻ, α 86.25(2), β 78.82(5), γ 67.88(5)°, Z = 2; R 0.069 for No 2091), while [( py )6/(4-mpy)6Ba(O2ClO2)2] (6) and (7), perhaps surprisingly, are isomorphous with (4), with O,O'-bidentate perchlorates replacing iodide in the coordination sphere (R 0.031 and 0.052 for No 2401 and 2204 respectively). With 3,5-dmpy (3,5-dimethylpyridine), strontium iodide yields a trans-six- rather than seven-coordinate adduct, [(3,5-dmpy)4SrI2] (8), the molecule conforming to crystallographic 4/m symmetry in the tetragonal space group I4/m, a 9.808(4), c 17.196(8) Ǻ, Z = 2; R 0.066 for No 608.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. V. Some Complexes With 3-Azapentane-1,5-diamine

1996 ◽  
Vol 49 (1) ◽  
pp. 73 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Tridentate Ligands ◽  
Nitrogen Base ◽  
Space Group ◽  
X Ray ◽  
Group 2 ◽  
Probable Space ◽  
Structural Characterizations

Syntheses and room-temperature single-crystal X-ray structural characterizations are recorded for an array of adducts of H2N(CN2)2NH(CH2)2NH2, ' dien ', with salts of Group 2 elements, MX2.n( dien ).[Mg( dien )2] Cl2 (1) is monoclinic, P 21/c, a 11.326(6), b 10.928(5), c 12.636(6) Ǻ, β 92.74(4)°, Z = 4 f.u .; R was 0.047 for No 1726 independent 'observed' (I > 3σ(I)) diffractometer reflections. [Mg( dien )2] Br2 (2) is monoclinic, P 21/c, a 9.541(7), b 14.55(1), c 11.894(8) Ǻ, β 100.42(5)°, Z = 4 f.u ., R 0.054 for No 1778. [Mg( dien )2] I2 (3) is isomorphous , a 9.969(2), b 14.907(2), c 12.300(3) Ǻ, β 100.02(2)°, R 0.039 for No 3180. In all three complexes, the two tridentate ligands are disposed mer in a six-coordinate MgN6 environment, the trans Mg-N(central) distances being somewhat shorter (2.161 (4)-2.181(9)Ǻ) than Mg-N(distal) (2.215(8)-2.249(4)Ǻ). [Ba(dien)3] Cl2 (4a) is orthorhombic, Pnaa , a 19.309(2), b 13.545(2), c 8.872(2)Ǻ, Z = 4 f.u ., R 0.055 for No 1070; the methanol disolvate (4b) is monoclinic, P 21/c, a 16.807(8), b 8.764(5), c 19.493(4) Ǻ, β 102.39(3)°, Z = 4 f.u ., R 0.11 for No 2613. A family of derivative structures (5)-(8), [M( dien )3] X2, M, X = Sr , Br (5), Sr , I(6), Ba , Br (7), Ba , I(8), have cells of half the volume (a ≈ 13.8, b ≈ 9, c ≈ 9.8 Ǻ), probable space group P21212, R 0.050, 0.061, 0.034, 0.037 for No 549, 914, 1044, 1801 respectively, with the cations disposed about crystallographic 2 axes with one disordered ligand . [ Ba( dien )3](ClO4)2 (9) is rhombohedral , R3c, a 10.240(2), c 45.19(1) Ǻ (hexagonal setting), Z = 6 f.u ., R 0.054 for No 508. Like (4)-(8), the barium environment is nine-coordinate with the three tridentate ligands here� disposed about a 3 axis through the metal.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. IV. Some Complexes of Group 2 Halides With Ethane-1,2-diamine

1996 ◽  
Vol 49 (1) ◽  
pp. 61 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Metal Salts ◽  
Nitrogen Base ◽  
X Ray ◽  
Structure Determinations ◽  
Group 2

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for a number of adducts of ethane-1,2-diamine (en) with Group 2 metal salts, MX2.n(en). [Mg(en)3] Br2.MeOH (1) is monoclinic, P 21/c, a 9.067(5), b 15.161(4), c 14.839(8) Ǻ, β 121.86(5)°, Z = 4 f.u .; R was 0.070 for No 1226 independent 'observed' (I > 3σ(I)) diffractometer reflections; [Mg(en)3] I2.MeOH (2) is triclinic, Pī , a 11.500(2), b 9.527(6), c 8.825(4) Ǻ, α 106.30(4), β 100.57(3), γ 90.28(4)°, Z = 2 f.u .; R 0.045 for No 3562. In (1) and (2), (Mg-N) are 2.20 and 2.19 Ǻ. [Ca(en)4]Br2 (3) is orthorhombic, Fddd , a 28.54(1), b 15.863(7), c 8.927(9) Ǻ, Z = 8 f.u .; Ca-N are 2.608(7) and 2.556(8) Ǻ. [ Sr (en)4] Cl2.2MeOH (4) is also orthorhombic, Fddd , a 26.627(8), b 15.388(4), c 11.313(4) Ǻ, Z = 8 f.u .; R 0.059 for No 535. [ Sr (en)4] Br2.2en (5) is tetragonal, I 41/a, a 9.215(7), c 27.678(3) Ǻ, Z = 4 f.u ., R 0.044 for No 657. [ Sr (en)4]I2.MeOH (6) is tetragonal, I41/amd, a 9.389(1), c 28.78(1) Ǻ, Z = 4. f.u ., R 0.040 for No 10. In (4), (5) and (6), Sr -N are 2.728(7), 2.718(7); 2.720(7), 2.703(7) and 2.75(2), 2.72(7) Ǻ. [ ClBa (en)3(en)(2/2)](∞ ׀ ∞) Cl (≡ BaCl2.4en) (7) is monoclinic, P 21, a 8.666(3), b 9.063(10), c 12.655(5) Ǻ, β 108.13(3)°, Z = 2 f.u ., R 0.048 for No 1479. In (1) and (2), magnesium is six-coordinate [Mg(N,N'- bidentate )3]; (3)-(6), calcium and strontium are eight-coordinate [M(N,N'- bidentate )4]; in (7), barium is nine-coordinate, one of the en ligands being bridging so that the complex is a single-stranded polymer generated by the 21 screw. Ba-Cl is 3.419(5) Ǻ, Ba -N bidentate en-N are 2.91(2)-2.97(3) Ǻ, and Ba -N monodentate en-N 2.92(1), 3.15(1) Ǻ.

Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. X. Some Mixed-Ligand Complexes of Group 2 Metal Halides With 2,2':6',2"-Terpyridine and Oxygen Donors

1996 ◽  
Vol 49 (1) ◽  
pp. 147 ◽  
Author(s):  
AF Waters ◽  
AH White
Keyword(s):  
Room Temperature ◽  
Mixed Ligand ◽  
The Other ◽  
Metal Halides ◽  
Nitrogen Base ◽  
X Ray ◽  
Group 2 ◽  
Oxygen Donors ◽  
Centrosymmetric Dimers ◽  
Structural Characterizations

Room-temperature single-crystal X-ray structural characterizations are recorded for a variety of adducts of Group 2 metal halides with 2,2':6',2?-terpyridine ( tpy ) from various hydroxylic solvents. [Mg( tpy )2][Mg( tpy )(OH2)3] Br4.PriOH (1) is triclinic, Pī, a 19.352(6), b 12.852(5), c 11.463(3) Ǻ, α 110.95(3), β 99.04(2), γ 98.81(3)°, Z = 2 f.u .; conventional R on ׀ F ׀ at convergence was 0.056 for No 4398 independent 'observed' (I > 3σ(I)) reflections. In the [Mg( tpy )2]2+ ion, Mg-N(central; distal) are 2.099(9), 2.09(1); 2.152(9)-2.212(8) Ǻ, while in [Mg( tpy )(OH2)3]2+, Mg-N(central; distal) are 2.139(7); 2.206(9), 2.222(9) Ǻ, while Mg-O trans to these are 2.042(6); 2.082(9), 2.097(8) Ǻ. [Mg( tpy )(OH2)2( MeOH )] Cl2 (2) is triclinic, Pī, a 14.049(7), b 8.354(4), c 8.301(2) Ǻ, α 74.25(3), β 73.05(3), γ 80.37(4)°, Z = 2 f.u., R 0.064 for No 2417. In the cation, Mg-N(central; distal) are 2.125(4); 2.203(4), 2.218(4) Ǻ; Mg-O( MeOH ) is trans to Mg-N(central), being 2.013(4) Ǻ; Mg-O(OH2) are 2.067(4) and 2.063(4) Ǻ. [CaCl2( tpy )( dmf )2 (3) ( dmf = N,N- dimethylformamide ) is monoclinic, C2/c, a 23.27(2), b 11.225(6), c 16.517(8) Ǻ, β 109.56(5)°, Z = 4 centrosymmetric dimers, R 0.061 for No 985. The calcium atoms are linked by a pair of μ-chlorines, CaCl2Ca, and are seven-coordinate, N3Ca(μ-Cl )4 being broadly coplanar in the equatorial plane of a pentagonal bipyramidal array, with the other chlorine and the dmf oxygen trans and axial.

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.

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