TY - JOUR
T1 - Salen-type compounds of calcium and strontium
AU - Sánchez, Mario
AU - Harvey, Melanie J.
AU - Nordstrom, Fredrick
AU - Parkin, Sean
AU - Atwood, David A.
PY - 2002/10/21
Y1 - 2002/10/21
N2 - Salen complexes of the heavy alkaline-earth metals, calcium and strontium, were prepared by the reaction of various salen(t-Bu)H2 ligands with the metals in ethanol. Six new calcium and strontium compounds, [Ca(salen-(t-Bu))(HOEt)2(thf)] (1), [Ca(salen(t-Bu))(HOEt)2] (2), [Ca(salpen(t-Bu))(HOEt)3] (3), [Ca(salophen(t-Bu))(HOEt)(thf)] (4), [Sr(salen(t-Bu))(HOEt)3] (5), and [Sr(salophen(t-Bu))(HOEt)(thf)2] (6), were formed in this way with the quatridentate Schiff-base ligands N,N′-bis(3,5-di-tert-butylsalicylidene)ethylenediamine (salen(t-Bu)H2), N,N′-bis(3,5-di-tert-butyl-salicylidene)-1,3-propanediamine (salpen(t-Bu)H2), and N,N′-o-phenylenebis(3,5-di-tert-butylsalicylideneimine (salophen-(t-Bu)H2). Initially, ammonia solutions of the metals were combined with the salen(t-Bu)H2 ligands, and in the reaction of strontium with salen(t-Bu)H2, the unusual tetrametallic cluster [{OC6H2(t-Bu)2 CHN(CH2)2NH2}Sr (μ3-salean(t-Bu)H2)Sr (μ3-OH)]2 (7) was produced (salean(t-Bu)H4 = N,N′-bis(3,5-di-tert-butyl-2-hydroxybenzyl)-ethylenediamine). In this compound, the imine bonds of the salen(t-Bu)H2 ligand were reduced to form the known ligands salean(t-Bu)H4 and (HO)C6H2(t-Bu)2CHN (CH2)2NH2. Compounds 1, 5, 6, and 7 were structurally characterized by single-crystal X-ray diffraction. Crystal data for 1 (C44H74CaN2O6): triclinic space group P1̄, a = 8.3730(10) Å, b = 14.8010(10) Å, c = 18.756(2) Å, α = 72.551(10)°, β = 81.795(10)°, γ = 78.031 (10)°, Z = 2. Crystal data for 5 (C38H64SrN2O5): monoclinic space group P21/c, a = 23.634(3) Å, b = 8.4660(10) Å, c = 24.451(3) Å, β = 101.138(10)°, Z = 4. Crystal data for 6 (C46H67N2O5Sr): orthorhombic space group P212121, a = 10.5590(2) Å, b = 16.2070(3) Å, c = 26.7620(6) Å, Z = 4. Crystal data for 7 (C98H156N8O8Sr4): triclinic space group P1, a = 14.667(1) Å, b = 15.670(1) Å, c = 18.594(2) Å, α = 92.26(1)°, β = 111.84(1)°, γ = 117.12(1)°, Z = 4.
AB - Salen complexes of the heavy alkaline-earth metals, calcium and strontium, were prepared by the reaction of various salen(t-Bu)H2 ligands with the metals in ethanol. Six new calcium and strontium compounds, [Ca(salen-(t-Bu))(HOEt)2(thf)] (1), [Ca(salen(t-Bu))(HOEt)2] (2), [Ca(salpen(t-Bu))(HOEt)3] (3), [Ca(salophen(t-Bu))(HOEt)(thf)] (4), [Sr(salen(t-Bu))(HOEt)3] (5), and [Sr(salophen(t-Bu))(HOEt)(thf)2] (6), were formed in this way with the quatridentate Schiff-base ligands N,N′-bis(3,5-di-tert-butylsalicylidene)ethylenediamine (salen(t-Bu)H2), N,N′-bis(3,5-di-tert-butyl-salicylidene)-1,3-propanediamine (salpen(t-Bu)H2), and N,N′-o-phenylenebis(3,5-di-tert-butylsalicylideneimine (salophen-(t-Bu)H2). Initially, ammonia solutions of the metals were combined with the salen(t-Bu)H2 ligands, and in the reaction of strontium with salen(t-Bu)H2, the unusual tetrametallic cluster [{OC6H2(t-Bu)2 CHN(CH2)2NH2}Sr (μ3-salean(t-Bu)H2)Sr (μ3-OH)]2 (7) was produced (salean(t-Bu)H4 = N,N′-bis(3,5-di-tert-butyl-2-hydroxybenzyl)-ethylenediamine). In this compound, the imine bonds of the salen(t-Bu)H2 ligand were reduced to form the known ligands salean(t-Bu)H4 and (HO)C6H2(t-Bu)2CHN (CH2)2NH2. Compounds 1, 5, 6, and 7 were structurally characterized by single-crystal X-ray diffraction. Crystal data for 1 (C44H74CaN2O6): triclinic space group P1̄, a = 8.3730(10) Å, b = 14.8010(10) Å, c = 18.756(2) Å, α = 72.551(10)°, β = 81.795(10)°, γ = 78.031 (10)°, Z = 2. Crystal data for 5 (C38H64SrN2O5): monoclinic space group P21/c, a = 23.634(3) Å, b = 8.4660(10) Å, c = 24.451(3) Å, β = 101.138(10)°, Z = 4. Crystal data for 6 (C46H67N2O5Sr): orthorhombic space group P212121, a = 10.5590(2) Å, b = 16.2070(3) Å, c = 26.7620(6) Å, Z = 4. Crystal data for 7 (C98H156N8O8Sr4): triclinic space group P1, a = 14.667(1) Å, b = 15.670(1) Å, c = 18.594(2) Å, α = 92.26(1)°, β = 111.84(1)°, γ = 117.12(1)°, Z = 4.
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U2 - 10.1021/ic020101t
DO - 10.1021/ic020101t
M3 - Article
C2 - 12377033
AN - SCOPUS:0037152371
SN - 0020-1669
VL - 41
SP - 5397
EP - 5402
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 21
ER -