Synthesis, Structures, and Photocurrent Responses of Polyoxo-Titanium Clusters with Oxime Ligands: From Ti₄ to Ti₁₈

Abstract

Six crystalline polyoxo-titanium clusters (PTCs) derived from oximes, namely, Ti(μ-O)(OMe)(L1) (PTC-125; HL1 = salicylaldoxime), H[Ti(μ-O)(μ-O)(OMe)(L1)] (PTC-126), Ti(μ-O)(μ-O)(O Pr)(OAc)(L2) (PTC-127; HL2 = salicylhydroxamic acid; HOAc = acetic acid), Ti(μ-O)(OEt)(L2) (PTC-128), Ti(μ-O)(μ-O)(OEt)(L2) (PTC-129), and Ti(μ-O)(μ-O)(μ-O)(OEt)(L3) (PTC-130; HL3 = acetoxime) have been solvothermally synthesized and structurally characterized. Compared with the reported solid-state monomer, dimer, trimer, and tetramer titanium oximes, these compounds possess high nuclearity structures in the range Ti, Ti, Ti, Ti, Ti, and Ti as a result of the presence of oxo bridges. Even though three examples of tetranuclear and hexanuclear derivatives have been documented, PTC-130 with a centrosymmetric Ti cluster core represents the currently highest PTC compound in the oxime system. In addition, Ti/oximate ratio by solvothermal synthesis in this work possessed a broad range from 0.83:1 to 9:1, different from the constant ratio of 1:1 in the reported ones. According to the solid-state UV-vis diffuse reflectance measurement, the existence of oxime ligands largely enhanced their visible light harvest. Furthermore, their photocurrent response properties are also studied.

Synthesis, structural and physicochemical characterization of a new type Ti6-oxo cluster protected by a cyclic imide dioxime ligand

“…Crystalline polyoxo-titanium clusters (PTCs) have attracted considerable attention the last years [1][2][3][4][5][6][7][8][9][10][11][12] due to their potential applications in catalysis, medicine, electro-optics, and nanotechnology. [13][14][15][16][17][18][19] In particular, the precise structural information of PTCs can help the understanding of the binding modes of sensitizers to Ti-O 20 surfaces and potential applications in photoelectronic [21][22][23][24] and photocatalytic chemistry.…”

“…[13][14][15][16][17][18][19] In particular, the precise structural information of PTCs can help the understanding of the binding modes of sensitizers to Ti-O 20 surfaces and potential applications in photoelectronic [21][22][23][24] and photocatalytic chemistry. 2,[25][26][27][28][29] Moreover, the development of more efficient TOC photocatalysts for waste water treatment and splitting of the water is a hot topic in renewable energy and environmental research.…”

The structural chemistry of titanium alkoxide derivatives with OH-substituted bidentate ligands

“…The 3.211 coordination mode was also found in another SA-substituted titanium alkoxide, viz. Ti 3 (Oi-Pr) 8 (SA) 2 [12] and the SA-substituted oxo derivative Ti 4 (OMe) 6 (SA) 4 , both being structurally unrelated to 3 [13]. This coordination of SA is in contrast to titanium alkoxide derivatives with aliphatic or aromatic aldoximate ligands without the OH group in ß-position, where the oximate NO group is always side-on coordinated to the same titanium atom.…”

Metal–Organic Frameworks Based on Group 3 and 4 Metals

“…Note that only representative MOFs based on group 3 and 4 metals (excluding Sc and Hf) since 2018 and previous MOF milestones are listed; b) Linkers are abbreviated as: ABTC = 3,3′,5,5′-azobenzene-tetracarboxylate; AZDC = azobenzene-3,3′-dicarboxylate; ATDB = 4,4′-(4-amino-4H-1,2,4-triazole-3,5-diyl)-dibenzoate; ATPC = 4′,4′′,4′′′,4′′′′-(anthracene-9,10-diylidenebis(methan-1,1-diyl-1-ylidene))tetrabiphenyl-4-carboxylate; ATBC = 4,4′,4′′,4′′′-(anthracene-9,10-diylidenebis(methan-1,1-diyl-1-ylidene)) tetrabenzoate; BDC = terephthalate; BTTC = benzotristhiophene carboxylate; BHPB = hexakis(4-(4-carboxyphenyl)phenyl)benzoate; BDHA = benzene-1,4-dihydroxamic acid; BDB = 4,4′-(benzene-1,3-diyl)dibenzoate; BTDB = 4,4′-(benzo[c] [1,2,5]thiadiazole-4,7-diyl)dibenzoate; BTBA = 4,4′,4′′-(1H-benzo-[d]imidazole-2,4,7-triyl)tribenzoate; BPDC = biphenyl-4,4′-dicarboxylate; BPyDC = 2,2′-bipyridyl-5,5′-dicarboxylate; BTB = 1,3,5-benzenetrisbenzoate; CPTPY = 4′-(4-carboxyphenyl)-terpyridine; BTB = benzene tribenzoate; CBTB = 4,4′,4′′,4′′′-(9H-carbazole-1,3,6,8-tetrayl)tetrabenzoate; DCDPS = 4,4′-dicarboxydiphenyl sulfone; DTPP = 5,15-di(3,4,5-trihydroxyphenyl)porphyrin; DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; EDDB = 4,4′-(ethyne-1,2-diyl)dibenzoate; FUM = fumarate; 2,6-NDC = naphthalene-2,6-dicarboxylate; HBCPB = 1,2,3,4,5,6-hexakis[3,5-bis(4-carboxyphenyl)phenoxymethyl]benzene; HCHC = hexakis(4-carboxyphenyl)hexabenzocoronene; H 6 CPB/HCBB = 1′,2′,3′,4′,5′,6′-hexakis(4carboxyphenyl)benzene; H 6 TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid; H 2 DHBQ = 2,5-dihydroxybenzoquinone; INA = isonicotinate; L-AA = L-Aspartic acid; MDIP = 3,3′,5,5′-tetracarboxydiphenylmethane; PDC = 2,5-pyridinedicarboxylate; P-2COOH = N,N′-di-(4-benzoic acid)-1,2,6,7-tetrachloroperylene-3,4,9,10-tetracarboxylic acid diimide; TCPP = meso-tetrakis(4-carboxylatephenyl)porphyrin; TTFTB = tetrathiafulvalene-tetrabenzoate; TDHT = 2,4,6-tri(3,4-dihydroxyphenyl)-1,3,5triazine; TCPC = 5,10,15-tris(p-carboxylphenyl)corrole; TBAPY = 1,3,6,8-tetrakis(p-benzoic acid)pyrene; TTFTB = tetrathiafulvalene tetrabenzoate; TPHB = 4,4′,4′′,4′′′,4′′′′,4′′′′-(triphenylene-2,3,6,7,10,11-hexayl)hexabenzoate; THPP = 5,10,15,20-tetrakis(3,4,5-trihydroxyphenyl)porphyrin); THBPP = 5,10,15,20-tetrakis(3,4,5-trihydroxybiphenyl)porphyrin; TPDC = 2′,5′-dimethyl-terphenyl-4,4′′-dicarboxylate; TTDA = 5′-(1H-tetrazol-5-yl)-1,1′:3′,1′′-terphenyl-4,4′′-dicarboxylate; TBCPB = 1,2,4,5-tetrakis [ Ti-oxo clusters are widely considered as a TiO 2 nanomaterial at a molecular level, and receive considerable attention due to their structural diversity as well as potential applications in catalysis, biomedicine and environments. [48] The number of Ti atoms in Ti-oxo clusters ranges from 3 to 32, including Ti 3 , [49][50][51][52] Ti 4 , [50,[52][53][54][55][56][57] Ti 5 , [57] Ti 6 ,…”

“…Ti–oxo clusters are widely considered as a TiO 2 nanomaterial at a molecular level, and receive considerable attention due to their structural diversity as well as potential applications in catalysis, biomedicine and environments. [ 48 ] The number of Ti atoms in Ti–oxo clusters ranges from 3 to 32, including Ti 3 , [ 49–52 ] Ti 4 , [ 50,52–57 ] Ti 5 , [ 57 ] Ti 6 , [ 51,52,54,55,57–64 ] Ti 7 , [ 57 ] Ti 8 , [ 54,64,65 ] Ti 9 , [ 51,55,63 ] Ti 10 , [ 66 ] Ti 11 , [ 54–56,63 ] Ti 12 , [ 57,62,66,67 ] Ti 14 , [ 50,56 ] Ti 16 , [ 54,55,61,66 ] Ti 18 , [ 51,57 ] Ti 19 , [ 63 ] Ti 20 , [ 66,68 ] and Ti 32 clusters. [ 69 ] In general, during the assembly of Ti–oxo clusters, it is vital to control the competition between acids and coordinating ligands.…”