Polyhedral platinadicarbaborane chemistry. The molecular structure and some NMR properties of [9,9-(PPh3)2-arachno-9,5,6-PtC2B7H11]

Abstract

The reaction of [Pt(PPh3)4] with [arachno-4,5-C2B7H13] in benzene solution at room temperature yields the arachno ten-vertex platinadicarborane [9,9-( PPh3)2-arachno-9,5,6-PtC2B7H11] as white air-stable needles (80%). Crystals are monoclinic, space group P21/n, with a = 1 433.9(3), b = 1 495.9(3), c = 1 852.5(4) pm, β = 105.89(2)°, and Z = 4. From 5 193 observed [I < 2σ(I)] data, the final R(RW) were 0.0376(0.0374) (406 variables). The structure is based on an arachno {B10H142-}-type ten-vertex {PtC2B7} skeleton with the Pt and two C atoms respectively in the 9,5 and 6 positions in the open face. The assigned 11B and 1H NMR chemical shifts have been measured and are briefly compared to those of the [arachno-4,5-C2B7H13] substrate.