Abstract The pure rotational spectrum of AsD2in the2B1ground electronic state was measured in the frequency region of 268–398 GHz by microwave spectroscopy. The AsD2radical was generated in a free-space cell by dc-glow discharge of a gaseous mixture of D2and He over arsenic powder. Fifty fine and hyperfine components of nine rotational transitions were measured and analyzed by least-squares methods determining the detailed molecular constants of AsD2: the rotational constants, the centrifugal distortion constants, the spin–rotation coupling constant with the centrifugal distortion terms, and the hyperfine coupling constants associated with the arsenic and deuterium nuclei. The harmonic force field of AsH2was determined from the centrifugal distortion constants, the equilibrium vibrational frequency of ν2mode of AsH2, and the inertial defects of AsH2and AsD2. The harmonic force field was used to calculate vibrational corrections to the rotational constants of both species and thus the zero-point average structures for both species were derived; AsH2: rz(AsH) = 1.53436(15) A, θz(HAsH) = 90.695(20)°, and AsD2: rz(AsD) = 1.52902(13) A, θz(DAsD) = 90.722(17)°, where the errors in parentheses are due to residual inertial defects of the corrected moments of inertia. From the difference between the rzstructures for AsH2and AsD2the restructure of AsH2is estimated to be re(AsH) = 1.5158(6) A, θe(HAsH) = 90.79(8)°.

中文翻译：

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AsD2(X̃2B1) 自由基的微波光谱：谐波力场和分子结构

摘要 利用微波光谱在268-398 GHz频率范围内测量了2B1基电子态AsD2的纯旋转光谱。AsD2 自由基是在自由空间电池中通过 D2 和 He 的气体混合物在砷粉上的直流辉光放电产生的。通过最小二乘法测量和分析九个旋转转变的 50 个精细和超精细分量，以确定 AsD2 的详细分子常数：旋转常数、离心畸变常数、自旋-旋转耦合常数与离心畸变项，以及超精细与砷和氘核相关的耦合常数。AsH2 的谐波力场由离心畸变常数、AsH2 ν2mode 的平衡振动频率确定，以及 AsH2 和 AsD2 的惯性缺陷。谐波力场用于计算两种物质旋转常数的振动修正，从而推导出两种物质的零点平均结构；AsH2: rz(AsH) = 1.53436(15) A, θz(HAsH) = 90.695(20)°, and AsD2: rz(AsD) = 1.52902(13) A, θz(DAsD) = 90.722 其中(17)°括号中的误差是由于修正惯性矩的残余惯性缺陷造成的。根据 AsH2 和 AsD2 的 rz 结构之间的差异，AsH2 的重组估计为 re(AsH) = 1.5158(6) A，θe(HAsH) = 90.79(8)°。和 AsD2: rz(AsD) = 1.52902(13) A, θz(DAsD) = 90.722(17)°，其中括号中的误差是由于修正惯性矩的残余惯性缺陷造成的。根据 AsH2 和 AsD2 的 rz 结构之间的差异，AsH2 的重组估计为 re(AsH) = 1.5158(6) A，θe(HAsH) = 90.79(8)°。和 AsD2: rz(AsD) = 1.52902(13) A, θz(DAsD) = 90.722(17)°，其中括号中的误差是由于修正惯性矩的残余惯性缺陷造成的。根据 AsH2 和 AsD2 的 rz 结构之间的差异，AsH2 的重组估计为 re(AsH) = 1.5158(6) A，θe(HAsH) = 90.79(8)°。