Synthesis and Crystal Structure of a Rhodium(II) Formamidinate Dimer with Axial Water and Methanol Molecules

Abstract

Much interest has been devoted to lantern-type dimer complexes with a direct metal-metal bond, due to their unique properties based on the metal-metal bond.1 Recently, lantern-type dimers have been used as building blocks in combination with axial linker ligands to produce assembled complexes with extended 1 -3 dimensional structures. 1 Rhodium(II) formamidinate dimers, [Rh2(4-R-pf)4] (4-R-pf -= N, N¢-bis(4-alkylphenyl) formamidinate anion), were reported to work as building blocks, although rhodium(II) carboxylate dimers ([Rh2(O2CR)4]) are still more common as building blocks. 1-3 1,4-Diisocyanobenzne (1,4-dib) coordinates to the rhodium(II) atoms through the crowded axial sites with four aryl groups of [Rh2(4-R-pf)4], because 1,4-dib has long and narrow coordinating isocyano arms. 2,3 We have reported crystal structures of 1-dimensinal polymer complexes, [Rh2(4-Me-pf)4(1,4-dib)]n·2n(C6H6) and [Rh2(4-Me-pf)4(1,4-dib)]n·2n(toluene), and a hexanuclear complex, [{Rh2(4-Me-pf)4}3(1,4-dib)2]·6H2O. 2,3 Although our attempts to obtain the assembled complexes using axial linkers The title compound of a lantern-type rhodium(II) dimer, [Rh2(4-Et-pf)2(O2CCF3)2(H2O)(MeOH)] (4-Et-pf -= N,N¢-bis(4-ethylphenyl)formamidinate anion), was isolated and the crystal structure was determined by the single-crystal X-ray diffraction method at 90 K. It crystallizes in the triclinic space group P1 with a = 10.866 (2)

Crystal Structure of <i>N</i>,<i>N</i>′-Bis(3,5-dichlorophenyl)formamidine

“…The difference in the C-N bond length may be related to the existence of the axial chloride ion at one side of the Ru2 II,III cationic dimer. 1 ] is considered to be due to the paramagnetic Ru2 II,III dimer core (S = 3/2). Table 2 Selected bond distances (Å) and angles (˚) Fig.…”

“…We have been engaging in the chemistry of the rhodium(II) and ruthenium(II,III) dimers with formamidinato ligands, and reported their crystal structures and their physico-chemical properties. 1,2 Structural reports on the formamidine ligands, themselves, are not so many, as to be expected, [3][4][5][6] although they are considered to give the important information when comparing the corresponding dinuclear complexes with the same formaminate ligands. In this study, we determined the crystal structure of N,N¢-bis (3,5-dichlorophenyl) formamidine (abbreviated as H(3,5-Cl2-pf)) by the X-ray diffraction method, and compared its structural parameters with those of the (3,5-Cl2-pf)ligand parts of [Rh2(3,5-Cl2-pf)4] 7 and [Ru2(3,5-Cl2-pf)4Cl].…”

Crystal Structure of a Lantern-Type Dirhodium(II) Complex with a <i>cis</i>-(2:2) Arrangement of Two Formamidinato and Two Trifluoroacetato Bridges

“…(1) and cis-[Rh2(4-Etpf)2(O2CCF3)2(MeOH)2] (2), where 4-Et-pf-= N,N¢-bis(4ethylphenyl)formamidinate anion. 3,4 They have the same dinuclear structure with similar dimensions other than the † Towhomcorrespondenceshouldbeaddressed. E-mail:handam@riko.shimane-u.ac.jp X-rayStructureAnalysisOnline2015,VOL.31 2.328(2)Åfor2).…”

“…E-mail:handam@riko.shimane-u.ac.jp X-rayStructureAnalysisOnline2015,VOL.31 2.328(2)Åfor2). 3,4 Comparedwithlantern-typeRh2dinuclear complexeswithN,N¢-bis(4-alkylphenyl)formamidinatobridging ligands, [5][6][7] thedinuclearcomplexesoftheformamidinatoligands withalkylgroupsatthe3and5positionsofthephenylringsare relatively limited in number. 1 Here, we report on the crystal structure of cis- (4-Me-pf -= N,N¢-di-ptolylformamidinateanion).…”

“…This could come from the stronger donating nature of nitrogen atoms (MeCN and pyz (pyrazine)) compared with that of oxygen atoms (MeOH and H2O). [3][4][5][6] There seems to be no important effect on the Rh-Rh bondlengthduetothedifferenceinthesubstitutedalkylgroups (MeandEt),theirnumbers,andpositionsonthephenylringsof theformamidinatoligands.…”