Dalton Transactions p. 3158 - 3169 (2007)
Update date:2022-08-04
Topics:
Bennett, Martin A.
Bhargava, Suresh K.
Messelhaeuser, Johannes
Priver, Steven H.
Welling, Lee L.
Willis, Anthony C.
When the ortho-metallated complexes cis-[Pt(κ2-C 6H3-5-R-2-PPh2)2] (R = H 1, Me 2) are either heated in toluene or treated with CO at room temperature, one of the four-membered chelate rings is opened irreversibly to give dinuclear isomers [Pt2(κ2-C6H3-5-R-2-PPh 2)2(-C6H3-5-R-2-PPh 2)2] (R = H 10, Me 11). A single-crystal X-ray diffraction study shows the Pt...Pt separation in 10 to be 3.3875(4) A. By-products of the reactions of 1 and 2 with CO are polymeric isomers (R = H 13, Me 14) in which one of the P-C ligands is believed to bridge adjacent platinum atoms intermolecularly. In contrast to the behaviour of 1 and 2, when cis-[Pt(κ2-C6H3-6-Me-2-PPh 2)2] (cis-3) is heated in toluene, the main product is trans-3, and reaction of cis-3 with CO gives a carbonyl complex [Pt(CO)(κ1-C-C6H3-6-Me-2-PPh 2)(κ2-C6H3-6-Me-2-PPh 2)] 15, in which one of the carbanions is coordinated only through the carbon. Formation of a dimer analogous to 10 or 11 is sterically hindered by the 6-methyl substituent. Comproportionation of 1 or 2 with [Pt(PPh 3)2L] (L = PPh3, C2H4) gives diplatinum(i) complexes [Pt2(-C6H 3-5-R-2-PPh2)2(PPh3)2] (R = H 16, Me 17). An X-ray diffraction study shows that 17 contains a pair of planar-coordinated metal atoms separated by 2.61762(16) A. There is no evidence for the formation of an analogue containing -C6H 3-6-Me-2-PPh2. The axial PPh3 ligands of 16 are readily replaced by ButNC giving [Pt2(-2-C 6H4PPh2)2(CNBut) 2] 18, which is protonated by HBF4 to form a -hydridodiplatinum(ii) salt [Pt2(-H)(-2-C6H 4PPh2)2(CNBut)2]BF 4 [21]BF4. The JPtPt values in [21]BF 4 and 18, 2700 Hz and 4421 Hz, respectively, reflect the weakening of the Pt-Pt interaction caused by protonation. Similarly, 16 and 17 react with the electrophiles iodine and strong acids to give salts of general formula [Pt2(-Z)(-C6H3-5-R-2-PPh2) 2(PPh3)2]Y (Y = Z = I, R = H 19+, Me 20+; Z = H, Y = BF4, PF6, OTf, R = H 22 +; Z = H, Y = PF6, R = Me 23+). A single-crystal X-ray diffraction study of [23]PF6 shows that the cation has an approximately A-frame geometry, with a Pt...Pt separation of 2.7888(3) A and a Pt-H bond length of 1.62(1) A, and that the 5-methyl substituents have undergone partial exchange with the 4-hydrogen atoms of the PPh2 groups of the bridging carbanion. The latter observation indicates that the added proton of [23]+ undergoes a reversible reductive elimination-oxidative addition sequence with the Pt-C(aryl) bonds. The Royal Society of Chemistry.
View MoreChangzhou Litong Chemical Co., Ltd.
website:http://www.litonchem.com/
Contact:+86-519-86301238
Address:Laoba Rd, Hutang town Changzhou Jiangsu
WENZHOU M&C FOREIGN TRADE CO.,LTD.
Contact:+86-577-88862917
Address:No.8 Liming West Road,Wenzhou,zhejiang,China
Taizhou Sunny Chemical Co.,Ltd
Contact:+86-523-86920899 +86-13951172783
Address:No.11 Xingyuang road, Gaoyong Chemical Industry Park, Gaogang Jiangsu China
Beijing Mediking Biopharm Co., Ltd.
Contact:+86-10-89753524/81760121/81769521
Address:Hongxianghong Incubator, Beiqijia Town, Changping district, Beijing, China
Hubei Onward Bio-Development Co., Ltd.
Contact:+86-718-8417012
Address:No.517,Shizhou Avenue,Enshi City,Hubei Province,China,445002
Doi:10.1016/j.bmcl.2009.10.031
(2009)Doi:10.1021/ol0710257
(2007)Doi:10.1039/b703761a
(2007)Doi:10.1039/b703943c
(2007)Doi:10.1039/b705344d
(2007)Doi:10.1055/s-2007-1000857
(2008)