Two Types of Heterometallic One-Dimensional Alignment Composed of Acetamidate-Bridged Dirhodium and Pivalamidate-Bridged Diplatinum Complexes

Abstract

Two types of heterometallic one-dimensional chains, [{Rh2(acam)4}{Pt2(piam)2(NH3)4}2]n(CF3SO3)4n·2nMeOH (2, where acam = acetamidate, piam = pivalamidate) and [{Rh2(acam)4}{Pt2(piam)2(NH3)4}]n(CF3CO2)2n·2nEtOH (3), have been synthesized and characterized by single-crystal X-ray analyses. The chain structures in 2 and 3 are composed of two kinds of dinuclear complexes, [Rh2(acam)4] (i.e., [Rh2]) and [Pt2(piam)2(NH3)4] (i.e., [Pt2]), where Rh and Pt atoms are axially linked by metal-metal bonds. In 2 and 3, each complex is one-dimensionally aligned as -{[Rh2]-[Pt2]-[Pt2]}n- or -{[Rh2]-[Pt2]}n-, respectively, in which different alignments are caused by different isomers of [Pt2] that are HH (head-head) and HT (head-tail) orientation of piam ligands and their hydrogen bonding modes. Considering the crystal structures and X-ray photoelectron spectra (XPS) measurements in 2 and 3, the oxidation states of the metal atoms are -{[Rh2(II,II)]-[Pt2(II,II)]-[Pt2(II,II)]}n- and -{[Rh2(II,II)]-[Pt2(II,II)]}n-, which are unchanged from those in the starting compounds. The diffuse reflectance spectra show that LUMOs are M-M σ-type orbitals. The gap between filled and vacant σ-type orbitals in 3 is narrower than that in 2, and is attributed to the relative higher destabilized filled σ-type orbitals caused by lower numbers of linking platinum atoms.

Linear One-Dimensional Coordination Polymers Constructed by Dirhodium Paddlewheel and Tetracyanido-Metallate Building Blocks

“…The use of other metal complexes as connectors between the paddlewheel units can lead to the formation of heterometallic one-dimensional coordination polymers, whose versatile chemical and physical properties, such as temperature dependent luminescence or modulation of their electronic structures, make those polymers promising materials [22][23][24][25]. An interesting approach to obtain this kind of heterometallic one-dimensional polymers is the use of platinum complexes to form {[Rh 2 ]-[Pt 2 ]-[Pt 2 ]} n chains, in which the different dimetallic units show direct Rh-Pt metal-metal bonds [26][27][28][29]. Paramagnetic [Rh 2 ]-[Pt-Cu-Pt] chains can be synthesized, also inserting a copper complex [30,31].…”

Heterometallic one-dimensional chain with tetradeca metal repetition constructed by amidate bridged dirhodium and pivalate bridged diplatinum complexes influenced by hydrogen bonding

“…[46][47][48] All 1-D chains in the crystal are parallel, as shown in Fig. 29,32 Also, as shown in Table 2 tances are also longer (3.2089(16) Å), resulting from the ligand characters. The Rh-Rh distances in 4 are 2.404(3) and 2.407(2) Å, the shortest among similar heterometallic 1-D complexes (Table 3).…”

“…Therefore, the metal species used in 1-D chains are restricted to metals that favour a d 8 configuration, such as Ir, 18 Pt, [6][7][8] Rh, [10][11][12][13]27,28 and Pd. [30][31][32][33][34] Although obtaining different metal alignments from 1 using a variety of metals is possible, 1 itself contains three parts that can be modulated: (1) We have made efforts to synthesize novel 1-D complexes with HOMO-LUMO interactions at the d z 2 orbital using acetamidate as the bridging ligands at [Rh 2 ]. 29 29 Considering that the metal oxidation states in 1 are [Rh(+2) 2 ] and [Pt(+2) 2 ], these Rh-Pt bonds are formed by HOMO-LUMO interactions of the d z 2 orbitals between Rh(+2) and Pt(+2) metals having d 7 and d 8 configurations, respectively.…”

“…16,17 Previously, we proposed heterometallic 1-D chains constructed from two or three types of metal species. 29,32,34 As shown in Scheme 2, the HOMO in [Rh 2 (acam) 4 ] (acam = acetamidate) is a δ* orbital resulting from strong π donation of the nitrogen atom in the amidate ligand destabilizing the δ*, leading to easy one electron oxidation to form [Rh 2 ] + . Taking advantage of these interactions using different metals, we have synthesized and reported a variety of heterometallic 1-D chains.…”

Assembled structures of tetrakis(biimidazole)dirhodium complexes hydrogen-bonded with common inorganic anions

“…They are constructed using not only coordination bonds, but also weak interactions such as -stacking or hydrogen bonding. We have investigated assembled structures of metal-metal-bonded dirhodium complexes (Kawamura et al, 1993Yang et al, 2000Yang et al, , 2001Yang et al, , 2006Takazaki et al, 2003;Fuma et al, 2004;Ebihara & Fuma, 2006a,b, 2013Fuma & Ebihara, 2006;Uemura & Ebihara, 2011Fuma et al, 2012;Uemura et al, 2014). In the assembled structures of the amidate-bridged dirhodium complexes, NH and O hydrogenbonding sites in amidate bridges played significant roles in the construction of the structures and determination of their properties (Yang et al, 2000(Yang et al, , 2001(Yang et al, , 2006Takazaki et al, 2003;Fuma et al, 2004;Ebihara & Fuma, 2006a,b;Fuma & Ebihara, 2006).…”