TY - JOUR
T1 - Synthesis and Structure of Unassociated Mono-, Di-, and Trithiolate Derivatives of Aluminum and Gallium
T2 - Investigation of Al-S and Ga-S π-Bonding
AU - Wehmschulte, Rudolf J.
AU - Ruhlandt-Senge, Karin
AU - Power, Philip P.
PY - 1995/5/1
Y1 - 1995/5/1
N2 - The synthesis and characterization of several sterically crowded aluminum and gallium thiolates are described. The major reason for these studies was the investigation of the possible occurrence of π-bonding in Al-S and Ga-S bonds and the determination of the steric requirements for the isolation of monomeric heavier main group 3 thiolates in the solid state. The compounds examined were RAl(SMes*)2 (R = n-Bu, 1; t-Bu, 2), Mes*2GaSR (Mes* = 2,4,6-t-Bu3C6H2, R = Me, 3; Ph, 4), n-BuGa(SMes*)2, (5) (t-Bu2AlSTrip)2 (6) (Trip = 2,4,6-i-Pr3C6H2), (THF)Al(STrip)3 (7). They were characterized by X-ray crystallography (1–3, 5–7) and by NMR and IR spectroscopy. The data indicate that the M-S, p-p, π-bonding is weak and has an upper limit of 8–9 kcal mol−1. Restricted rotation around an M-S bond was detected only in the cases of Mes*2GaSMe (3) and Mes*2-GaSPh (4). Crystal data at 130 K with Mo Kα (λ = 0.710 69 Å) (2, 5–7) or Cu Kα (λ = 1.541 78 Å) (1, 3) radiation; 1, n-BuAl(SMes*)2, C40H67AlS2, a = 18.563(5) Å, b = 27.171(11) Å, c = 32.089(4) Å, orthorhombic, Z = 16 (two independent molecules), space group Pbca, R = 0.087 for 6746 (I > 2σ(I)) data; 2, t-BuAl(SMes*)2, C40H67AlS2, a = 17.375(9) Å, b = 27.982(10) Å, c = 17.868(8) Å, β = 112.29(2)°, Z = 8 (two independent molecules), monoclinic, space group P21/c, R = 0.082 for 8425 (I > 2σ(I)) reflections; 3, Mes*2GaSMe, C37H61-GaS, a = 33.654(8) Å, b = 10.433(4) Å,c = 20.258(8) Å, Z = 8, orthorhombic, space group Pbcn, R = 0.066 for 3164 (I > 2σ(I)) reflections; 5, n-BuGa(SMes*)2, C40H67GaS2, a = 18.521(8) Å, b = 27.342(10) Å, c = 32.046(12) Å, orthorhombic, Z = 16 (two independent molecules), space group Pbca, R = 0.144 for 3297 (I > 2σ(I)) reflections; 6, (t-Bu2AlSTrip)2, C46H82A12S2, a = 20.820(8) Å,b= 14.598(6) Å, c = 16.118(4) Å, Z = 4, orthorhombic, space group Pna21 R = 0.062 for 2469 (I > 2.5σ(I)) data; 7, (THF)Al(STrip)3-0.5C6H14, C52H84-AlOS3, a = 15.589(6) Å,b= 13.622(5) Å, c = 26.308(12) Å, β = 99.88(2)°, Z = 4, monoclinic, space group P21/c, R = 0.075 for 5697 (I > 3σ(I)) data.
AB - The synthesis and characterization of several sterically crowded aluminum and gallium thiolates are described. The major reason for these studies was the investigation of the possible occurrence of π-bonding in Al-S and Ga-S bonds and the determination of the steric requirements for the isolation of monomeric heavier main group 3 thiolates in the solid state. The compounds examined were RAl(SMes*)2 (R = n-Bu, 1; t-Bu, 2), Mes*2GaSR (Mes* = 2,4,6-t-Bu3C6H2, R = Me, 3; Ph, 4), n-BuGa(SMes*)2, (5) (t-Bu2AlSTrip)2 (6) (Trip = 2,4,6-i-Pr3C6H2), (THF)Al(STrip)3 (7). They were characterized by X-ray crystallography (1–3, 5–7) and by NMR and IR spectroscopy. The data indicate that the M-S, p-p, π-bonding is weak and has an upper limit of 8–9 kcal mol−1. Restricted rotation around an M-S bond was detected only in the cases of Mes*2GaSMe (3) and Mes*2-GaSPh (4). Crystal data at 130 K with Mo Kα (λ = 0.710 69 Å) (2, 5–7) or Cu Kα (λ = 1.541 78 Å) (1, 3) radiation; 1, n-BuAl(SMes*)2, C40H67AlS2, a = 18.563(5) Å, b = 27.171(11) Å, c = 32.089(4) Å, orthorhombic, Z = 16 (two independent molecules), space group Pbca, R = 0.087 for 6746 (I > 2σ(I)) data; 2, t-BuAl(SMes*)2, C40H67AlS2, a = 17.375(9) Å, b = 27.982(10) Å, c = 17.868(8) Å, β = 112.29(2)°, Z = 8 (two independent molecules), monoclinic, space group P21/c, R = 0.082 for 8425 (I > 2σ(I)) reflections; 3, Mes*2GaSMe, C37H61-GaS, a = 33.654(8) Å, b = 10.433(4) Å,c = 20.258(8) Å, Z = 8, orthorhombic, space group Pbcn, R = 0.066 for 3164 (I > 2σ(I)) reflections; 5, n-BuGa(SMes*)2, C40H67GaS2, a = 18.521(8) Å, b = 27.342(10) Å, c = 32.046(12) Å, orthorhombic, Z = 16 (two independent molecules), space group Pbca, R = 0.144 for 3297 (I > 2σ(I)) reflections; 6, (t-Bu2AlSTrip)2, C46H82A12S2, a = 20.820(8) Å,b= 14.598(6) Å, c = 16.118(4) Å, Z = 4, orthorhombic, space group Pna21 R = 0.062 for 2469 (I > 2.5σ(I)) data; 7, (THF)Al(STrip)3-0.5C6H14, C52H84-AlOS3, a = 15.589(6) Å,b= 13.622(5) Å, c = 26.308(12) Å, β = 99.88(2)°, Z = 4, monoclinic, space group P21/c, R = 0.075 for 5697 (I > 3σ(I)) data.
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U2 - 10.1021/ic00114a017
DO - 10.1021/ic00114a017
M3 - Article
AN - SCOPUS:33751156705
SN - 0020-1669
VL - 34
SP - 2593
EP - 2599
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 10
ER -