Accessibility Studies of Sol-Gel Processed Phosphane-Substituted Iridium(I) Complexes in the Interphase

Abstract

Keywords: Iridium / Immobilization / Sol-gel processes / Accessibility studies / NMR spectroscopyThe synthesis of the T-silyl functionalized, and therefore solgel processable, Vaska complex [IrCl(CO){(C 6 H 5 ) 2 PC 6 H 4 -(CH 2 ) 4 Si(OMe) 3 } 2 ] [4(T 0 )] succeeded by reaction of [Ir(µ-Cl)(COE) 2 ] 2 (COE = cyclooctene; 1) with the phosphane (C 6 H 5 ) 2 PC 6 H 4 (CH 2 ) 4 Si(OMe) 3 [3(T 0 )] in the presence of carbon monoxide. Subsequently, 4(T 0 ) was co-polycondensed with five equivalents of (MeO) 3 Si(CH 2 ) 3 C 6 H 4 (CH 2 ) 3 Si(OMe) 3 {5[Ph(1,4-C 3 T 0 ) 2 ]} to give the polysiloxane-bound complex X1. For accessibility studies of the reactive centers, X1 was

Design, Synthesis, Characterization of Novel Ruthenium(II) Catalysts: Highly Efficient and Selective Hydrogenation of Cinnamaldehyde to (E)-3-Phenylprop-2-en-1-ol

“…The absence of the CH 3 O signal at δ C = 36.8 which belongs to (CH 3 O) 3 Si in [3-(2-aminoethyl)-aminopropyl]trimethoxysilane co-ligand after sol-gel reaction of complex 1 to form xerogel X1 was the major difference recorded in spectra; this is in agreement with the immobilization of the desired hybrid Ru(II) complexes. In addition, the total disappearance of groups in X1 (Figure 6b) compared with complex 1 (Figure 6a) provides good confirmation that the sol-gel process has proceeded to completion [22,23,24,25,26,27,28,29,30,31,32,33,34].…”

Design, Synthesis, Characterization of Novel Ruthenium(II) Catalysts: Highly Efficient and Selective Hydrogenation of Cinnamaldehyde to (E)-3-Phenylprop-2-en-1-ol

“…The absence of the CH 3 O signal at δ C = 36.8 which belongs to (CH 3 O) 3 Si in [3-(2-aminoethyl)-aminopropyl]trimethoxysilane co-ligand after sol-gel reaction of complex 1 to form xerogel X1 was the major difference recorded in spectra; this is in agreement with the immobilization of the desired hybrid Ru(II) complexes. In addition, the total disappearance of groups in X1 (Figure 6b) compared with complex 1 (Figure 6a) provides good confirmation that the sol-gel process has proceeded to completion [22,23,24,25,26,27,28,29,30,31,32,33,34].…”

Supported and Non-Supported Ruthenium(II)/Phosphine/[3-(2-Aminoethyl)aminopropyl]trimethoxysilane Complexes and Their Activities in the Chemoselective Hydrogenation of trans-4-Phenyl-3-butene-2-al

“…The use of an asymmetric diamine co-ligand such as [3-(2-aminoethyl)aminopropyl]trimethoxy-silane caused the loss of the C 2 axis, resulting in a splitting of the 31 P{ 1 H}-NMR resonances of 1 , 2 , X1 and X2 into AB patterns [ 14 , 27 ]. The phosphorous chemical shifts and the 31 P - 31 P coupling constants ( J pp = 30–36 Hz) of the desired complexes suggest that the phosphine ligand was positioned trans to the diamine, with trans dichloro atoms, to form the kinetically favored trans -Cl2Ru(II) isomer, as seen in Figure 3 .…”

“…Solid-state 29 Si-NMR provided further information about the silicon environment and the degree of functionalization [ 9 , 10 , 17 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. In all cases, the organometallic/organic fragment of the precursor molecule was covalently grafted onto the solid, and the precursors were, in general, attached to the surface of the polysiloxane by multiple siloxane bridges.…”

Synthesis and Spectrosopic Identification of Hybrid 3-(Triethoxysilyl)propylamine Phosphine Ruthenium(II) Complexes

“…Solid-state 29 Si-NMR provided further information about the silicon environment and the degree of functionalization [1,30]. In all cases, the organometallic/organic fragment of the precursor molecule was covalently grafted onto the solid, and the precursors were, in general, attached to the surface of the polysiloxane by multiple siloxane bridges.…”

Design, Synthesis, Characterization of Novel Ruthenium(II) Catalysts: Highly Efficient and Selective Hydrogenation of Cinnamaldehyde to (E)-3-Phenylprop-2-en-1-ol

“…The absence of the CH 3 O signal at δ C = 36.8 which belongs to (CH 3 O) 3 Si in [3-(2-aminoethyl)-aminopropyl]trimethoxysilane co-ligand after sol-gel reaction of complex 1 to form xerogel X1 was the major difference recorded in spectra; this is in agreement with the immobilization of the desired hybrid Ru(II) complexes. In addition, the total disappearance of groups in X1 (Figure 6b) compared with complex 1 (Figure 6a) provides good confirmation that the sol-gel process has proceeded to completion [22,23,24,25,26,27,28,29,30,31,32,33,34].…”

Supported and Non-Supported Ruthenium(II)/Phosphine/[3-(2-Aminoethyl)aminopropyl]trimethoxysilane Complexes and Their Activities in the Chemoselective Hydrogenation of trans-4-Phenyl-3-butene-2-al

“…The use of an asymmetric diamine co-ligand such as [3-(2-aminoethyl)aminopropyl]trimethoxy-silane caused the loss of the C 2 axis, resulting in a splitting of the 31 P{ 1 H}-NMR resonances of 1 , 2 , X1 and X2 into AB patterns [ 14 , 27 ]. The phosphorous chemical shifts and the 31 P - 31 P coupling constants ( J pp = 30–36 Hz) of the desired complexes suggest that the phosphine ligand was positioned trans to the diamine, with trans dichloro atoms, to form the kinetically favored trans -Cl2Ru(II) isomer, as seen in Figure 3 .…”

“…Solid-state 29 Si-NMR provided further information about the silicon environment and the degree of functionalization [ 9 , 10 , 17 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. In all cases, the organometallic/organic fragment of the precursor molecule was covalently grafted onto the solid, and the precursors were, in general, attached to the surface of the polysiloxane by multiple siloxane bridges.…”

Synthesis and Spectrosopic Identification of Hybrid 3-(Triethoxysilyl)propylamine Phosphine Ruthenium(II) Complexes

“…Solid-state 29 Si-NMR provided further information about the silicon environment and the degree of functionalization [1,30]. In all cases, the organometallic/organic fragment of the precursor molecule was covalently grafted onto the solid, and the precursors were, in general, attached to the surface of the polysiloxane by multiple siloxane bridges.…”

Design, Synthesis, Characterization of Novel Ruthenium(II) Catalysts: Highly Efficient and Selective Hydrogenation of Cinnamaldehyde to (E)-3-Phenylprop-2-en-1-ol

“…The absence of the CH 3 O signal at δ C = 36.8 which belongs to (CH 3 O) 3 Si in [3-(2-aminoethyl)-aminopropyl]trimethoxysilane co-ligand after sol-gel reaction of complex 1 to form xerogel X1 was the major difference recorded in spectra; this is in agreement with the immobilization of the desired hybrid Ru(II) complexes. In addition, the total disappearance of groups in X1 (Figure 6b) compared with complex 1 (Figure 6a) provides good confirmation that the sol-gel process has proceeded to completion [22,23,24,25,26,27,28,29,30,31,32,33,34].…”

Supported and Non-Supported Ruthenium(II)/Phosphine/[3-(2-Aminoethyl)aminopropyl]trimethoxysilane Complexes and Their Activities in the Chemoselective Hydrogenation of trans-4-Phenyl-3-butene-2-al

“…The use of an asymmetric diamine co-ligand such as [3-(2-aminoethyl)aminopropyl]trimethoxy-silane caused the loss of the C 2 axis, resulting in a splitting of the 31 P{ 1 H}-NMR resonances of 1 , 2 , X1 and X2 into AB patterns [ 14 , 27 ]. The phosphorous chemical shifts and the 31 P - 31 P coupling constants ( J pp = 30–36 Hz) of the desired complexes suggest that the phosphine ligand was positioned trans to the diamine, with trans dichloro atoms, to form the kinetically favored trans -Cl2Ru(II) isomer, as seen in Figure 3 .…”

“…Solid-state 29 Si-NMR provided further information about the silicon environment and the degree of functionalization [ 9 , 10 , 17 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. In all cases, the organometallic/organic fragment of the precursor molecule was covalently grafted onto the solid, and the precursors were, in general, attached to the surface of the polysiloxane by multiple siloxane bridges.…”

Synthesis and Spectrosopic Identification of Hybrid 3-(Triethoxysilyl)propylamine Phosphine Ruthenium(II) Complexes

“…Solid-state 29 Si-NMR provided further information about the silicon environment and the degree of functionalization [1,30]. In all cases, the organometallic/organic fragment of the precursor molecule was covalently grafted onto the solid, and the precursors were, in general, attached to the surface of the polysiloxane by multiple siloxane bridges.…”