A Nanoscopic Molecular Cadmium Phosphonate Wrapped in a Hydrocarbon Sheath

Abstract

Dedicated to Dr. Manfred Flad on the occasion of his 90th birthdayPreparing a material that has particles of uniform dimension has been one of the biggest challenges for chemists as well as material scientists. The traditional ways of imparting order at the nanoscopic level have changed since the synthesis of fullerene clusters.[1] The use of techniques such as epitaxy and metal-organic chemical vapor deposition (MOCVD) have been used extensively in this regard. The synthesis of giant inorganic molecules, such as polyoxoanions, [2] Al 77 , [3] and Ga 84 [4] clusters are examples of inorganic counterparts of fullerenes. The synthesis of metal phosphonates using organometallic routes in recent years has led to the realization of a series of oligomeric transition-metal and main-group-metal phosphonates. [5, 6] In all these reports, the size of the oligomeric structure is highly dependent on the substituent on the metal center as well as at the phosphorus center. The metal phosphonates can be synthesized either using metal precursor-phosphonic acid interactions via an acid exchange or by starting from metal alkyls/amides/alcoholates by elimination of alkanes/amines/alcohols. [5][6][7] It has been demonstrated that metals belonging to the same group of the periodic table yield molecular phosphonates of the same topology if the substituents on the metal and phosphorus centers are kept the same. Although examples of zinc phosphonates following both the synthetic methodologies have been reported, there have been no examples of molecular cadmium phospho-

Nuclearity Control in Molecular Iron Phosphates through Choice of Iron Precursors and Ancillary Ligands

“…However the other peripheral iron atom Fe (3), is coordinated to a chlorine ligand resulting in a FeO 3 Cl coordination environment in distorted tetrahedral geometry. Overall the geometry observed in 7 is (17); Fe(2)ÀO(1)-Fe(1) 120.19 (14); Fe(2)À O(1)ÀFe(3) 120.40 (14); Fe(1)ÀO(1)ÀFe(3) 119.31 (14); O(14)ÀFe(1)À O(23) 88.63 (13); O(14)ÀFe(1)ÀO(11) 166.19 (13); O(23)ÀFe(1)ÀO(11) 90.67 (13); O(14)ÀFe(1)ÀO(1) 98.04 (12).…”

“…The ratio of Fe II peak to Fe III peak is 72:28 and the presence of Fe III impurity in this sample has been attributed to the aerobic oxidation of the Fe II complex (Figure 14). However, in case of the mixed valent trimer 3, instead of the expected (14); O(7)À Fe(1)ÀO(6) 89.59 (14); O(3)ÀFe(1)ÀO(6) 166.31 (13); O(7)ÀFe(1)ÀO(1) 96.70 (17); O(3)ÀFe(1)ÀO(1) 97.0(2); O(6)ÀFe(1)ÀO(1) 96.1(2); O(7)À Fe(1)ÀO(2) 167.64 (14); O(3)ÀFe(1)ÀO(2) 87.79 (14); O(6)ÀFe(1)ÀO(2) 86.93 (14); O(1)ÀFe(1)ÀO(2) 95.46 (16); O(7)ÀFe(1)ÀO(10) 84.51 (13); O(3)ÀFe(1)ÀO(10) 83.74 (15); O(6)ÀFe(1)ÀO(10) 83.11 (15); O(1)ÀFe(1)À O(10) 178.56(8); O(2)ÀFe(1)ÀO(10) 83.30 (14). Figure 13.…”

“…Therefore organophosphates and organophosphonic acids have been extensively used to synthesize polynuclear complexes by many research groups. [7][8][9][10][11][12][13][14] Depending upon the reaction conditions, the coordination mode of both types of ligands vary, often leading to either completely unprecedented or highly desirable results. A major advantage associated with mono-organophosphates over organophosphonates, is their diminutive tendency to form layered insoluble solids, which allowed us to synthesize a large number of polynuclear complexes.…”

Synthesis and characterization of a family of tetranuclear manganese(iii) phosphonate complexes

“…Transition-metal phosphonate complexes have received a lot of attention in recent years primarily because of their potential applications in catalysis, ion exchange, proton conductivity, intercalation chemistry, photochemistry and material chemistry. [9][10][11][12] Several metal phosphonate compounds that contain vanadium, 13 aluminium, 14 copper, 15,16 cobalt, 8 zinc, [16][17][18] cadmium, 19 and iron 20 have been prepared so far. Recently utilization of the phosphonate to prepare polynuclear manganese complexes has received an increasing attention, and three kinds of target clusters with higher nuclearity, one hexa-, one icosa-and one dodeca-nuclear manganese aggregate have been obtained using bulky phosphonates (phenylphosphonate, benzylphosphonate and cyclohexenephosphonate) as ligands.…”

A novel 3D coordination polymer [Cd15(μ4-Mtta)12(μ3-Mtta)6(μ3-SO4)4(μ3-OH)4]: Synthesis, structure and solid properties

“…Seen in Fig. 1, a l 4 -Mtta linkers three Cd2 and a Cd1 ions and gives a Cd2-Cd2 distance (3.7000(3) Å), smaller than Cd1-Cd2 (4.097 Å), thus suggesting a stronger intermetallic interaction in the Cd 3 (OH) (SO 4 )(l 3 -Mtta) 3 cage than in the Cd 2 (Mtta) 2 center [8]. In contrast, each l 3 -Mtta links two Cd2 and a Cd1, and meanwhile shows a thermodynamic disorder of methyl, as depicted in Scheme 1, about the C 2 axes parallel respectively to a, b and c for the energy degeneracy of two possible forms.…”