Abstract
The synthesis and characterization of several Pt(ii) complexes, including formyl complexes, based on the PCP-type pincer ligands C6H4[CH2P(iPr)2]2 (iPrPCP) and C6H4[CH2P(tBu)2]2 (tBuPCP) are described. The chloride complex (iPrPCP)PtCl (6) and the unsaturated cationic complexes [(PCP)Pt]+X− (X = OTf−, BF4−) (1, 7), based on both PCP ligands, were prepared and the latter reacted with carbon monoxide to give the corresponding cationic carbonyl complexes [(PCP)Pt(CO)]+X− (X = OTf−, BF4−) (2, 8a). Hydride nucleophilic attack on both carbonyl complexes resulted in rare neutral platinum formyl complexes (iPrPCP)Pt(CHO) (3) and (tBuPCP)Pt(CHO) (9). Complex 3 undergoes decarbonylation to the corresponding hydride complex within hours at room temperature, while the bulkier complex 9 is more stable and undergoes complete decarbonylation only after 3–4 d. This observation demonstrates the very significant steric effect of the ligand on stabilization of the corresponding formyl complexes. Reaction of complex 9 with triflic acid resulted in the carbonyl complex [(tBuPCP)Pt(CO)]+ OTf− (8b) with liberation of H2, an unusual transformation for a metal formyl. Reaction with methyl triflate resulted in the Fischer carbene-type complex, the methoxy-methylidene [(tBuPCP)Pt(CHOCH3)]+OTf− (11). The X-ray structures of complexes 2, 6, 8a and 11 were determined.
| Original language | English |
|---|---|
| Pages (from-to) | 5692-5700 |
| Number of pages | 9 |
| Journal | Journal of the Chemical Society. Dalton Transactions |
| Issue number | 48 |
| DOIs | |
| Publication status | Published - Dec 4 2006 |
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Reactivity and stability of platinum(ii) formyl complexes based on PCP-type ligands. The significance of sterics. / Vuzman, Dana; Poverenov, Elena; Diskin-Posner, Yael; Leitus, Gregory; Shimon, Linda J.W.; Milstein, David.
In: Journal of the Chemical Society. Dalton Transactions, No. 48, 04.12.2006, p. 5692-5700.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Reactivity and stability of platinum(ii) formyl complexes based on PCP-type ligands. The significance of sterics
AU - Vuzman, Dana
AU - Poverenov, Elena
AU - Diskin-Posner, Yael
AU - Leitus, Gregory
AU - Shimon, Linda J.W.
AU - Milstein, David
PY - 2006/12/4
Y1 - 2006/12/4
N2 - The synthesis and characterization of several Pt(ii) complexes, including formyl complexes, based on the PCP-type pincer ligands C6H4[CH2P(iPr)2]2 (iPrPCP) and C6H4[CH2P(tBu)2]2 (tBuPCP) are described. The chloride complex (iPrPCP)PtCl (6) and the unsaturated cationic complexes [(PCP)Pt]+X− (X = OTf−, BF4−) (1, 7), based on both PCP ligands, were prepared and the latter reacted with carbon monoxide to give the corresponding cationic carbonyl complexes [(PCP)Pt(CO)]+X− (X = OTf−, BF4−) (2, 8a). Hydride nucleophilic attack on both carbonyl complexes resulted in rare neutral platinum formyl complexes (iPrPCP)Pt(CHO) (3) and (tBuPCP)Pt(CHO) (9). Complex 3 undergoes decarbonylation to the corresponding hydride complex within hours at room temperature, while the bulkier complex 9 is more stable and undergoes complete decarbonylation only after 3–4 d. This observation demonstrates the very significant steric effect of the ligand on stabilization of the corresponding formyl complexes. Reaction of complex 9 with triflic acid resulted in the carbonyl complex [(tBuPCP)Pt(CO)]+ OTf− (8b) with liberation of H2, an unusual transformation for a metal formyl. Reaction with methyl triflate resulted in the Fischer carbene-type complex, the methoxy-methylidene [(tBuPCP)Pt(CHOCH3)]+OTf− (11). The X-ray structures of complexes 2, 6, 8a and 11 were determined.
AB - The synthesis and characterization of several Pt(ii) complexes, including formyl complexes, based on the PCP-type pincer ligands C6H4[CH2P(iPr)2]2 (iPrPCP) and C6H4[CH2P(tBu)2]2 (tBuPCP) are described. The chloride complex (iPrPCP)PtCl (6) and the unsaturated cationic complexes [(PCP)Pt]+X− (X = OTf−, BF4−) (1, 7), based on both PCP ligands, were prepared and the latter reacted with carbon monoxide to give the corresponding cationic carbonyl complexes [(PCP)Pt(CO)]+X− (X = OTf−, BF4−) (2, 8a). Hydride nucleophilic attack on both carbonyl complexes resulted in rare neutral platinum formyl complexes (iPrPCP)Pt(CHO) (3) and (tBuPCP)Pt(CHO) (9). Complex 3 undergoes decarbonylation to the corresponding hydride complex within hours at room temperature, while the bulkier complex 9 is more stable and undergoes complete decarbonylation only after 3–4 d. This observation demonstrates the very significant steric effect of the ligand on stabilization of the corresponding formyl complexes. Reaction of complex 9 with triflic acid resulted in the carbonyl complex [(tBuPCP)Pt(CO)]+ OTf− (8b) with liberation of H2, an unusual transformation for a metal formyl. Reaction with methyl triflate resulted in the Fischer carbene-type complex, the methoxy-methylidene [(tBuPCP)Pt(CHOCH3)]+OTf− (11). The X-ray structures of complexes 2, 6, 8a and 11 were determined.
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U2 - 10.1039/b711444c
DO - 10.1039/b711444c
M3 - Article
SP - 5692
EP - 5700
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 48
ER -