Structure of the copper tripodal Schiff base complex {tris[4-(2-thienyl)-3-aza-κN-3-butenyl]amine-κN}copper(I) tetrafluoroborate

The copper Schiff base complex {tris[4-(2-thienyl)-3- aza-~N-3-butenyl]amine-~N} copper(I) tetrafluoroborate, [Cu{N(CTHgNS)3 }]+.BF4- (I), crystallizes with the cation residing in a general position and two disordered tetrafluoroborate anions residing on twofold axes. The cation has approximate threefold symmetry and the copper(I) geometry is distorted trigonal pyramidal with coordination from the apical tertiary amine N atom and the three azomethine N atoms but not from the S atoms of the three thiophene moieties. The principal bond lengths are Cu-- Napical 2.300 (5) ,~ and mean Cu--Nequatorial 1.994 (4) A,, with a mean Cu-..S contact of 3.270 (2) A

Structure of 5-phenyldibenzophosphole

C~sH13P, Mr = 260.3, orthorhombic, Pbc2~ [alternative setting of Pca2~ (No.29)], a = 8.486 (2), b = 12.387 (3), c = 26.244 (5) A, V= 2759 (1) A 3, Z = 8, Dx=l.25gcm -3, a(MoKa)=0.71073A, i z= 1.8 cm-~, F(000) = 1088, T= 288 K, R = 0.050 for 1512 observed reflections. The structure contains two 5-phenyldibenzophosphole molecules per asymmetric unit and these have almost identical conformations in the crystal lattice [as defined by the torsion angles C(ll)--P(1A)--C(31)--C(32) 32.0(5) and C(41)-- P(2A)--C(61)~C(62) 34.1 (6)°]. The central fivemembered rings in both molecules have envelope conformations, with the P atom 0.136(15) and 0.104(15) A from the relevant four-C-atom plane; the dibenzophosphole moieties are both bowed slightly, with the aromatic rings bent in a direction away from the pendant phenyl ring bonded to the P atom [dihedral angles between the plane of the C atoms of the central ring and the aromatic rings are in the range 1.1 (4)-3.0 (4)°]. There is also a small rotation about the central C--C bond as shown by the relevant torsion angles which are in the range 0.2 (5)-3.3 (6) ° . Difference maps show that there is disorder in the crystal lattice in that each molecule is disordered over two sites [a major and a minor one in each case; occupancies 0.89 and 0.11 for molecule (1) and 0.95 and 0.05 for molecule (2)]. For the minor sites, only the P atoms could be detected. Main dimensions are: P--C(phenyl) 1.841(9), 1.846 (10) A, P--C(dibenzophosphole) 1.808 (9)- 1.838(10), mean 1.819 (9) A, phosphole ring C--P--C 88.9 (4) and 89.5 (4) °, exocyclic C--P--C 101.7 (4)-104.2 (4), mean 103.0 (4) °

Structural Studies of Steric Effects in Phosphine Complexes: Dimers of Bis-{dithiocyanato(1-phenyl-dibenzophosphole)mercury(II)} Associate with Significant Hg−N and Hg−S Interdimer Interactions

The title compound, [Hg(SCN)2(C6H5)P(C12H8)]2, exists as a dimer with two-fold crystallographic symmetry in the solid state with the Hg atoms linked by bridging N- and S-thiocyanato atoms. There are four primary bonds to each Hg atom, Hg−N, 2.771(4) A, Hg−P, 2.4084(11) Å and two Hg−S, 2.4565(10) Å and 2.6055(13) Å, result-ing in a distorted trigonal pyramidal geometry about the metal centre. The dimers associate about inversion centres to form infinite one-dimensional chains by weaker Hg⋅⋅⋅N 3.178(5) Å and Hg⋅⋅⋅S 3.6027(14) Å interactions, giving an overall distorted octahedral coordination geometry for each Hg atom. The Hg⋅⋅⋅P bond lies approximately orthogonal to the ⋅⋅Hg⋅⋅Hg⋅⋅ chain and the benzophosphole group forms a \u27sandwich5 preventing interactions between the Hg(SCN)2 moieties in neighbouring chains

Structural Studies of Steric Effects in Phosphine Complexes. Part XII1. Synthesis, Characterisation, and Crystal and Molecular Structure of Bis(trifluoroacetato)(trimesitylphosphine)mercury(II) Dimer, [Hg(CF3C02)2P(mesityl)3]2

The synthesis and crystal and molecular structure of the bis(trifluoroacetato)(trimesitylphospine)mercuryiII) dimer are reported. Crystals are triclinic, space group Pl with one centrosymmetric dimer in a unit cell of dimensions a = 12.854(3), b = = 12.877(4), c = 12.405(2) A, a = 107.34(2), (J = 118.55(2), y = 63.65 (2) 0 • The structure was solved by the heavy atom method and refined by full-matrix least-squares calculation, R = 0.051 for 1656 observed reflections measured by diffractometer. The mercury coord!nation is characterized by three strong nearly coplanar bonds (Hg-P 2.415(5), Hg-0(12) 2.29(2), Hg-0 2.18(2) A) and two weaker bonds (Hg-0(22) 2.95(2) and Hg-0(11)\u27 2.66(2) A). The Pmes3 ligand has a regular propeller conformation (Hg-P-C-C torsion angles 45-49 °), enlarged C-P-C angles (mean 112.6(9) 0 ), decreased Hg-P-C angles (mean 106.2(6) 0 ), and a maximum cone angle of 208 °. Bridging in the solid state utilizes both oxygens of the CFsC02 moiety; the complex becomes monomeric in dichloroethane solution. Infrared, 1H, and 31P NMR data are discussed

Avoiding genetic bottlenecks in broodstock selection

Peer reviewed: NoNRC publication: Ye