Visible light absorption of binuclear TiOCoII charge-transfer unit assembled in mesoporous silica

Abstract

Grafting of Co II (NCCH 3 )

Towards a Molecular Level Understanding of the Multi-Electron Catalysis of Water Oxidation on Metal Oxide Surfaces

“…Units with appropriate redox potentials are capable of driving a water oxidation catalyst, others reduce CO 2 to CO or formate. Todate, a dozen different systems featuring Ti or Zr as acceptor and a first or second row transition metal as donor center have been developed [86][87][88][89][90][91][92][93][94][95][96][97]. The detailed structure of several units on the surface of mesoporous silica supports, including the ZrOCo II system shown in Fig.…”

Controlled Assembly of Hetero-binuclear Sites on Mesoporous Silica: Visible Light Charge-Transfer Units with Selectable Redox Properties

“…When monitoring the uptake of the donor metal precursor Co II (NCCH 3 ) 2 Cl 2 into MCM-41 or Ti-MCM-41 particles from acetonitrile solution by UV-Vis spectroscopy of the supernatant over a 2 hr period, more than an order of magnitude faster rate was observed for the silica sieve that contains tripodally anchored (OSi) 3 TiOH groups on the pore surface. As shown in Table 1 The much larger uptake of Ce III and Co II into Ti-MCM-41 is attributed to the higher acidity, hence higher reactivity of TiOH groups with metal precursors compared to SiOH groups.…”

A Periodic Walk through a Series of First‐Row, Oxido‐Bridged, Heterodimetallic Molecules: Synthesis and Structure

“…[12,[20][21][22] Compounds 2a-f are ideal for forming heterodimetallic adducts with 1 due to their single open coordination site and significant chemical and electrochemical stability. [23,24] In this report we discuss the synthesis of a series of complexes that include synthetically accessible first-row transition metals, [ 2 (3a-f; M = Mn, Fe, Co, Ni, Cu, Zn; OTf = trifluoromethylsulfonate), along with their structural, electronic, and electrochemical properties. The earlier transition metals (M = Sc, Ti, V, [25] Cr [13] ) were not included since their M 2+ oxidation states are unstable under the conditions utilized when forming these heterodimetallic linkages.…”

“…By utilizing cyclic voltammetry, the Ti 4+/3+ halfwave potential (E 1/2 ) in 1 is found to be at -2.26 V vs. the ferrocene/ferrocinium (Fc/Fc + ) redox couple. This redox potential was assigned based on comparison with the non-metallated ligand tmtaa(H) 2 , which lacks this feature. Formation of the dative oxo linkage with a transition metal atom anodically shifts the potential of the Ti 4+/3+ redox couple (E 1/2 = -1.53 V for 3c versus E 1/2 = -1.68 V for 3f ).…”

“…Heterodimetallic, oxido-bridged, metal-to-metal charge-transfer chromophores are known to drive electron-transfer processes including oxidation, [1][2][3][4] reduction [5,6] and complete redox cycles. [7,8] However, the bulk of these studies focus on solid-state systems, and spectroscopic techniques available to study them are limited.…”