Synthesis, crystal structure, and cytotoxicity studies of titanacalix[4 and 8]arene complexesCCDC 1554491-3. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c8dt01992d

• Main Authors: Miller-Shakesby, David M, Nigam, Shubhanchi, Hughes, David L, Lopez-Estelles, Enrique, Elsegood, Mark R. J, Cawthorne, Christopher J, Archibald, Stephen J, Redshaw, Carl
• Format: Journal Article
• Language: English
• Published: 10.07.2018
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt01992d

Reaction of 5,11,17,23-tetra- tert -butyl-dihydroxy-26,28-bis(2-pentoxy)calix[4]arene (L(OH) 2 (Opentyl) 2 ) with [TiCl 4 ] afforded the dichlorotitanoacalix[4]arene complex [TiCl 2 L(O) 2 (Opentyl) 2 ] ( 1 ) in good yield. Hydrolysis of 1 led to the isolation of the complex {[TiL(O) 3 (Opentyl)] 2 (μ-OH)(μ-Cl)} ( 2 ). Reaction of 5,11,17,23,29,35,41,47- p-tert -butyl-49,50,51,52,53,54,55,56-octapropoxycalix[8]arene (L′(Opropyl) 8 ) with [TiCl 4 ] in refluxing toluene afforded, following work-up, a 35 : 65 mixture ( 3 ) of the complex [Ti(NCMe)Cl] 2 [TiCl(μ-O)] 2 L′ and the silicone grease derived complex [Ti(NCMe)Cl] 2 [Ti(μ-O)] 2 [OSi(CH 3 ) 2 OSi(CH 3 ) 2 O]L′ in which the grease replaces two chloride ligands. The molecular structures of 1 · 2MeCN , 2 · 7¼MeCN , and 3 · 10MeCN have been determined. The complexes were studied using in vitro cell assays and were found to have CC 50 values in the range 111-186 μM, i.e. they have low toxicity. The molecular structures and cytotoxicity of titanocalix[4 and 8]arene complexes are reported.