Kroeker S, Hanna J V, Wasylishen R E, Ainscough E W, Brodie A M
Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4J3, Canada.
J Magn Reson. 1998 Nov;135(1):208-15. doi: 10.1006/jmre.1998.1580.
Phosphorus-31 CP/MAS NMR spectra of two linear bis(tribenzylphosphine)cuprate(I) salts reveal significant anisotropy in the one-bond 31P, 63,65Cu J tensors. The parallel and perpendicular components of 1J(31P, 63Cu), for example, are +2.0 and +1.3 kHz, respectively. The well-characterized space group and point symmetry in one of these compounds greatly simplifies the 31P lineshape analysis, thus dispensing with the need to make assumptions about the interaction tensors involved. This offers an unique opportunity to study DeltaJ by calculating dipolar coupling constants from known internuclear distances, and by using zero-field nuclear quadrupole resonance spectroscopy to obtain the magnitudes of the 63/65Cu nuclear quadrupole coupling constants, CQ. Copper-63 CQ values in these complexes exceed 80 MHz, proving to be the largest reported for copper(I) phosphines. Phosphorus-31 NMR spectra of non-spinning samples at three applied magnetic fields are also presented, along with lineshape calculations based on full-matrix Zeeman-quadrupolar Hamiltonian diagonalization. It is shown that exact 31P lineshape calculations provide the relative signs of CQ, the isotropic J-coupling, and the effective dipolar coupling constant. This appears to be the first unambiguous determination of Delta1J(31P, 63/65Cu).
两种线性双（三苄基膦）铜酸盐（I）盐的磷 - 31 交叉极化/魔角旋转核磁共振谱显示，一键 31P - 63、65Cu J 张量存在显著的各向异性。例如，1J(31P, 63Cu) 的平行和垂直分量分别为 +2.0 和 +1.3 kHz。其中一种化合物具有明确的空间群和点对称性，极大地简化了 31P 线形分析，从而无需对所涉及的相互作用张量进行假设。这提供了一个独特的机会来研究 ΔJ，方法是根据已知的核间距计算偶极耦合常数，并使用零场核四极共振光谱来获取 63/65Cu 核四极耦合常数 CQ 的大小。这些配合物中的铜 - 63 CQ 值超过 80 MHz，是报道的铜（I）膦中最大的。还展示了在三个外加磁场下非旋转样品的磷 - 31 核磁共振谱，以及基于全矩阵塞曼 - 四极哈密顿量对角化的线形计算。结果表明，精确的 31P 线形计算给出了 CQ 的相对符号、各向同性 J 耦合以及有效偶极耦合常数。这似乎是首次明确测定 Δ1J(31P, 63/65Cu)。
