TY - JOUR
T1 - Variable-Valent Re≡NAr Species. A Family of ReVINAr Amide Complexes and Their RevNAr Imine Precursors Related by Oxygen Atom Transfer
AU - Dirghangi, Bimal Kumar
AU - Menon, Mahua
AU - Banerjee, Sangeeta
AU - Chakravorty, Animesh
PY - 1997
Y1 - 1997
N2 - Imide complexes of type RevCl3(X-SB)(NC6H4Y(p)), with X, Y= H, Me, OMe, Cl have been synthesized where X-SB is the Schiff base of pyridine-2-carboxaldehyde (the corresponding complex is 4), 2-acetylpyridine (5), 2-benzoylpyridine (6), and anilines, p-XC6H4NH2. Treatment of 4 or 5 (but not 6) with aqueous nitric acid in acetonitrile afforded ReVICl3(X-PA)(NC6H4Y(p)), 7, via oxygen atom transfer (X-PA -monoanionic picolinamide). In the structures of 5(X=C1,Y=C1), 6(OMe,OMe), and 7(Me,Me), the chlorine atoms are meridionally disposed in a ReCl3N3 coordination sphere. The trans influence of the imide nitrogen considerably lengthens the ReN(pyridine) bond. The ReNC6H4Y(p) group has the triple-bonded linear moiety, Re≡N-C. The amide group in 7(Me,Me) is planar. In 6(OMe,OMe) the two aryl rings on the imine function block water attack and hence amide formation. The rhenium(VI)-rhenium(V) E1/2 values for 4-6 (0.7-1,0 V vs SCE) are much higher than that for 7 (E1/2 ∼ 0.15 V), which displays the rhenium(VH)-rhenium(VI) couple near 1.6 V. Six EPR hyperfine lines are observed for solutions of 7 at room temperature (giso ∼ 1.91 ; Aav ∼ 490 G). Crystal data for the complexes are as follows: 5(C1,C1), empirical formula C19H15Cl5N3Re, crystal system monoclinic, space group P21/c, a = 13.360(6) Å, b = 12.110(3) Å, c = 14.954(9) Å, β= 111.41(4)°, V = 2252.4(1.7) Å3,Z = 4; 6(OMe,OMe), empirical formula C26H23Cl3N3O2Re, crystal system orthorhombic, space group Pbca, a = 12.079(5) Å, b = 17.083(9) Å, c = 26.049(9) Å, V = 5375.4(4.0) Å3, Z = 8; 7(Me,Me), empirical formula C20H18Cl3N3ORe, crystal system monoclinic, space group P21/c, a = 7.071(2) Å, b = 17.541(6) Å, c = 16.857(8) Å, β= 100.59(3)°, V = 2055.3(1.3) Å3, Z = 4.
AB - Imide complexes of type RevCl3(X-SB)(NC6H4Y(p)), with X, Y= H, Me, OMe, Cl have been synthesized where X-SB is the Schiff base of pyridine-2-carboxaldehyde (the corresponding complex is 4), 2-acetylpyridine (5), 2-benzoylpyridine (6), and anilines, p-XC6H4NH2. Treatment of 4 or 5 (but not 6) with aqueous nitric acid in acetonitrile afforded ReVICl3(X-PA)(NC6H4Y(p)), 7, via oxygen atom transfer (X-PA -monoanionic picolinamide). In the structures of 5(X=C1,Y=C1), 6(OMe,OMe), and 7(Me,Me), the chlorine atoms are meridionally disposed in a ReCl3N3 coordination sphere. The trans influence of the imide nitrogen considerably lengthens the ReN(pyridine) bond. The ReNC6H4Y(p) group has the triple-bonded linear moiety, Re≡N-C. The amide group in 7(Me,Me) is planar. In 6(OMe,OMe) the two aryl rings on the imine function block water attack and hence amide formation. The rhenium(VI)-rhenium(V) E1/2 values for 4-6 (0.7-1,0 V vs SCE) are much higher than that for 7 (E1/2 ∼ 0.15 V), which displays the rhenium(VH)-rhenium(VI) couple near 1.6 V. Six EPR hyperfine lines are observed for solutions of 7 at room temperature (giso ∼ 1.91 ; Aav ∼ 490 G). Crystal data for the complexes are as follows: 5(C1,C1), empirical formula C19H15Cl5N3Re, crystal system monoclinic, space group P21/c, a = 13.360(6) Å, b = 12.110(3) Å, c = 14.954(9) Å, β= 111.41(4)°, V = 2252.4(1.7) Å3,Z = 4; 6(OMe,OMe), empirical formula C26H23Cl3N3O2Re, crystal system orthorhombic, space group Pbca, a = 12.079(5) Å, b = 17.083(9) Å, c = 26.049(9) Å, V = 5375.4(4.0) Å3, Z = 8; 7(Me,Me), empirical formula C20H18Cl3N3ORe, crystal system monoclinic, space group P21/c, a = 7.071(2) Å, b = 17.541(6) Å, c = 16.857(8) Å, β= 100.59(3)°, V = 2055.3(1.3) Å3, Z = 4.
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U2 - 10.1021/ic9701322
DO - 10.1021/ic9701322
M3 - Article
AN - SCOPUS:0000888337
SN - 0020-1669
VL - 36
SP - 3595
EP - 3601
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 17
ER -